National Mower Lawn Mower 68 DL User Manual
MODEL 68 SR TRIPLEX MOWER  
MODEL 68 DL TRIPLEX MOWER  
OWNER'S MANUAL  
Includes Operation, Maintenance and Parts List  
700 Raymond Ave., P.O. Box 14299  
NATIONAL MOWER CO.  
St. Paul, Minnesota 55114-0299, U.S.A.  
Phone (651) 646-4079 – Fax (651) 646-2887  
www.nationalmower.com  
June 2003  
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NATIONAL 68 SR & DL TRIPLEX  
TABLE OF CONTENTS  
Warranty ................................................................................................... 2  
Introduction ............................................................................................... 3  
Safety Information .................................................................................... 4  
Safety and Control Decals........................................................................ 7  
Receipt of Shipment ............................................................................... 11  
Uncrating Instructions............................................................................. 11  
Assembly ................................................................................................ 12  
Preparation ............................................................................................. 14  
Operation ................................................................................................ 14  
Maintenance ........................................................................................... 18  
Maintenance Record .............................................................................. 26  
Troubleshooting ...................................................................................... 27  
Parts List ................................................................................................. 28  
Frame & Running Gear ................................................................... 28  
Running Gear & Misc. Parts - 68 DL............................................... 30  
Seat Mounting & Belt Guards.......................................................... 31  
Drive Mechanism - Upper Portion ................................................... 32  
Drive Mechanism - Middle Portion .................................................. 34  
Drive Mechanism - Lower Portion ................................................... 35  
Drive Mechanism - 68 DL................................................................ 36  
Rear Axle & Differential ................................................................... 38  
Wing Cutting Units........................................................................... 40  
Rear Cutting Unit ............................................................................. 42  
Skids, Reel End Shields & Guards ................................................. 44  
Roller & Standard Scrapers ............................................................ 45  
Roller Scraper Kit, Dial-A-Height™ ................................................. 46  
Dial-A-Height™ Roller Adjuster Kit ................................................. 47  
Dial-A-Height™ Adjuster ................................................................. 48  
Safety Switches ...................................................................................... 49  
Electrical Diagrams................................................................................. 50  
Electrical Parts........................................................................................ 51  
Specifications.......................................................................................... 52  
Parts Ordering Information ..................................................................... 53  
Declaration of Conformity ....................................................................... 55  
INTRODUCTION  
Before operating mower, carefully and completely read  
this manual. The contents provide you with an  
understanding of safety instructions and controls during  
normal operation and maintenance. Understand all  
safety precautions provided in the manuals. Review  
control functions and operation of the mower. Do not  
operate the mower unless all controls function as  
described in this manual. Review recommended  
lubrication, maintenance, and adjustments.  
This manual has been prepared by National Mower  
Company as an aid to users in the assembly, safe  
operation, maintenance, adjustment and ordering re-  
placement parts. Additional information will gladly be  
furnished by calling or writing the manufacturer or his  
authorized agent.  
Please furnish us with the Model Number, Serial Number  
and Date of Purchase when contacting us about your  
machine. Designations of right, left, front add rear are  
used as if the operator was sitting in the mower seat.  
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SAFETY INFORMATION  
safety guards are in place at all times, except during  
servicing.  
The safety alert words below are used in this manual to  
identify potentially hazardous conditions. Their  
definitions are:  
Keep all nuts, bolts, and screws tight.  
3. OPERATION  
DANGER means "IMMINENTLY HAZARDOUS  
SITUATION! If not avoided, WILL RESULT in death or  
serious injury."  
Wear approved safety glasses or goggles when operating  
the mower.  
Do not allow children to operate mower. Do not allow  
adults to operate mower without proper instruction.  
WARNING means "POTENTIALLY HAZARDOUS  
SITUATION! If not avoided, COULD RESULT in death or  
injury."  
Do not carry passengers. Keep children and pets at a safe  
distance from an operating mower. Stop the mower if  
anyone approaches the mower.  
CAUTION  
means "POTENTIALLY HAZARDOUS  
SITUATION! If not avoided, MAY RESULT in minor or  
moderate injury." It may also be used to alert against  
unsafe practices.  
Disengage all cutting-unit clutches and shift into neutral  
before attempting to start the engine. Disengage main  
clutch before shifting cutting-unit clutches.  
Disengage power to the cutting units and stop the engine  
before leaving the operator’s position.  
The safety alert triangle symbols on your mower point  
out important safety precautions.  
Disengage power to the cutting units and stop the engine  
before making any repairs or adjustments.  
Disengage power to the cutting units when transporting or  
not in use.  
These symbols mean:  
Take all possible precautions when leaving the mower  
unattended, including shifting into neutral, setting the  
parking brake, stopping the engine and removing the  
ignition key.  
ATTENTION!  
PERSONAL SAFETY IS INVOLVED!  
BECOME ALERT!  
Watch for dangerous traffic when crossing or near road-  
ways.  
OBEY THE MESSAGE!  
Neverdirectthedischargeofmaterialfromoperatingreels  
toward bystanders nor allow anyone near the mower.  
NATIONAL MOWER SAFE OPERATING  
PRACTICES  
The mower and reels should be stopped and inspected  
for damage after striking a foreign object. The damage  
should be repaired before restarting and operating the  
mower.  
1. TRAINING  
Know the control functions and how to stop quickly. READ  
THE OWNER’S MANUAL.  
Proceed as follows when mowing:  
• Mow only in daylight or in good artificial light.  
2. PREPARATION  
• Never make a cutting height adjustment while the en-  
gine is running.  
Clear the work place of objects which might be picked up  
by the blades and thrown.  
• Shut the engine off when removing grass or unclogging  
reels.  
Handle fuel with CAUTION - it is highly flammable.  
• Use an approved fuel container.  
This machine is to be used only as a grass cutter or lawn  
mower.  
• Never remove the fuel tank cap or add fuel to a running  
or hot engine. Never fill the fuel tank indoors. Wipe up  
spilled fuel immediately.  
Never operate the mower while using drugs, medications,  
or alcohol. Safe operation requires complete and unim-  
paired attention. Never allow anyone to operate the  
mower when their alertness or coordination is impaired.  
• Open garage doors to allow ventilation if engine is run  
inside – exhaust fumes are dangerous. Do not run en-  
gine in any enclosed area.  
Do not wear loose clothing or loose shoelaces, which may  
become entangled in mower controls or drive compo-  
nents.  
Keep the mower in safe operating condition. Make sure  
that all safety switches are operating properly and all  
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Do not mow in reverse, unless absolutely necessary.  
Always look down and behind before and during reverse  
motion.  
Never mow while people, especially children, or pets are  
nearby.  
Keep in mind that the operator or user is responsible for  
accidents or hazards occurring to other people or their  
property.  
Shut off and raise the cutting units before operating the  
mower at transport speed. (Model 68 DL only.)  
Donotreversebatteryconnections.Damagetothemower  
can result. Battery gases are explosive and can cause  
death or injury. Keep open flames, sparks, and smoking  
materials away from batteries. Battery fluid contains  
sulfuric acid. Contact with skin, eyes, or clothing can  
cause chemical burns. Wash immediately and seek  
medical assistance. Wear protective clothing and safety  
glasses when handling a battery. (Model 68 DL only.)  
Do not carry passengers.  
All drivers should seek and obtain professional and  
practical instruction. Such instruction should emphasize:  
• the need for care and concentration when working with  
ride-on machines;  
• control of a ride-on machine sliding on a slope will not  
be regained by the application of the brake. The main  
reasons for loss of control are:  
4. HILL OPERATION  
Donotstoporstartsuddenlywhengoinguphillordownhill.  
Mowupanddownthefaceofsteepslopes—neveracross  
steepslopes. Donotexceedaslopeof15o inanydirection.  
• insufficient wheel grip;  
• being driven too fast;  
• inadequate braking;  
Reduce travel speed on slopes and in sharp turns to  
prevent tipping or loss of control. Use extreme caution  
when changing direction on slopes.  
• the type of machine is unsuitable for the task: do not  
use mower for unsuitable tasks;  
Watch for holes in the terrain and other hidden hazards.  
Do not shift into neutral and coast downhill.  
• lack of awareness of the effect of ground conditions,  
especally slopes;  
• hitching and load distribution: do not hitch or tow  
other devices.  
Useextremecarewhenmowingneardropoffsorembank-  
ments. The mower could roll over if a wheel goes over the  
edge, or if an edge caves in.  
2. PREPARATION  
Ifmowerstopsgoinguphill, disengagepowertothecutting  
units and slowly back down.  
Gasoline(petrol)ishighlyflammable.  
WARNING  
Store fuel in containers specifically  
designed for this purpose. Refuel outdoors only. Do  
not smoke while refuelling. Add fuel before starting  
the engine. Never remove the cap of the fuel tank or  
addfuelwhiletheengineisrunningorwhentheengine  
is hot. If fuel is spilled, do not attempt to start the  
engine but move the machine away from the area of  
spillage and avoid creating any sources of ignition  
until fuel vapors have dissipated. Replace all fuel  
tanks and container caps securely.  
5. MAINTENANCE  
Never store the mower, with fuel in the tank, inside a  
building where fumes could reach an open flame or spark.  
Allow the engine to cool before storing in any enclosure.  
Keep the engine free of grass, leaves or excessive grease  
to reduce a fire hazard.  
Do not change the engine governor settings or overspeed  
the engine.  
While mowing, always wear substantial footwear and  
long trousers. Do not operate the equipment when  
barefoot or wearing open sandals.  
Keep non-skid surfaces clean. Replace the non-skid  
material if worn, damaged, or missing.  
Wear appropriate safety gear, including safety glasses  
and gloves, while servicing the mower.  
Thoroughly inspect the area where the equipment is to be  
used and remove all objects which can be thrown by the  
machine.  
Replace faulty silencers.  
ISO SAFE OPERATING PRACTICES  
Before using, always visually inspect to see that the reels,  
bed knives, and cutting unit assemblies are not worn or  
damaged. Replacewornordamagedreelsandbedknives  
in sets to preserve balance.  
1. TRAINING  
Read the instructions carefully. Be familiar with the  
controls and the proper use of the equipment.  
Onmulti-reelmachines, takecareasrotatingonereelcan  
cause other reels to rotate.  
Never allow children or people unfamiliar with these  
instructions to use the lawnmower. Local regulations can  
restrict the age of the operator.  
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SAFETY INFORMATION  
Disengage drive to attachments when transporting or not  
in use.  
3. OPERATION  
Do not operate the engine in a confined space where  
dangerous carbon monoxide fumes can collect.  
Stop the engine and disengage drive to attachment:  
• before refuelling;  
Mow only in daylight or good artificial light.  
• before removing the grass catcher;  
• before making height adjustment;  
• before cleaning blockages;  
Beforeattemptingtostarttheengine,disengageallcutting  
unit clutches and shift into neutral.  
Do not use on slopes of more than 15°.  
Remember there is no such thing as a safe slope. Travel  
ongrassslopesrequiresparticularcare. Toguardagainst  
overturning:  
• before checking, cleaning, or working on the mower;  
• after striking a foreign object. Inspect the mower for  
damage and make repairs before restarting and oper-  
ating the equipment.  
• do not stop or start suddenly when going up or downhill;  
• engage clutch slowly, always keep machine in gear, es-  
pecially when travelling downhill;  
Reduce the throttle setting during engine shutdown and  
turn the fuel off at the conclusion of mowing.  
• machine speeds should be kept low on slopes and dur-  
ing tight turns;  
4. MAINTENANCE AND STORAGE  
Keep all nuts, bolts, and screws tight to be sure the  
equipment is in safe working condition.  
• stay alert for humps and hollows and other hidden haz-  
ards;  
Never store the equipment with fuel in the tank inside a  
building where fumes can reach an open flame or spark.  
• never mow across the face of the slope, unless the ma-  
chine is designed for this purpose.  
Allow the engine to cool before storing in any enclosure.  
Watch out for traffic when crossing or near roadways.  
To reduce the fire hazard, keep the engine, silencer,  
battery compartment, and fuel storage area free of grass,  
leaves, or excessive grease.  
Stop the reel rotation before crossing surfaces other than  
grass.  
Never direct discharge of material toward bystanders or  
allow anyone near the machine while in operation.  
Replace worn or damaged parts for safety.  
If the fuel tank has to be drained, this should be done  
outdoors.  
Never operate the lawnmower with defective guards, or  
without safety devices in place.  
When machine is to be parked, stored, or left unattended,  
lower the cutting means unless a positive mechanical  
lock is used.  
Do not change the engine governor setting or overspeed  
the engine. Operating the engine at excessive speed can  
increase the hazard of personal injury.  
Be careful during adjustment of the machine to prevent  
entrapment of the fingers between moving blades and  
fixed parts of the machine.  
Before leaving the operator's position,  
• disengage the power take-off and lower the cutting units;  
• shift into neutral and set the parking brake;  
• stop the engine and remove the key.  
Onmulti-reelmachines, takecareasrotatingonereelcan  
cause other reels to rotate.  
Disengage drive to the cutting units, stop the engine,  
remove the ignition key, and disconnect the spark plug  
wire:  
CALIFORNIASAFEOPERATINGPRACTICES  
• before cleaning blockages or unclogging chute;  
Mowers used in California, USA are required by law (CA  
PRC 4442 & CA H & SC 13005) to have their engines  
equipped with spark arresters when operating in flam-  
mable vegetation. Arresters must be obtained from your  
engine dealer and are not available from National Mower  
Company.  
• before checking, cleaning, or working on the machine;  
• after striking a foreign object. Inspect the lawn mower  
for damage and make repairs before restarting and op-  
eration the lawn mower;  
• if lawn mower starts to vibrate abnormally (check imme-  
diately).  
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NATIONAL 68 SR & DL TRIPLEX  
SAFETY AND CONTROL DECALS  
Safety decals and instructions are located on the mower near the controls or near areas of potential hazards. Worn,  
damaged, or loose decals must be replaced. The decal part number and the location of the decal on the mower are  
listed next to each decal.  
07584 – TRANSPORT CLUTCH PEDAL  
(Model 68 DL)  
(locatedontopsurfaceofenginebeltguard)  
(locatedontopsurfaceofengine  
07581-MAINENGINECLUTCH  
LEVER  
belt guard)  
Pressing the pedal will cause the mower to  
runinhigh-speedtransportmode. Operate  
Move lever backward to put  
the transport clutch by slowly pressing the  
clutchinneutralposition,forward  
pedal with your left foot. Releasing the  
to cause mower to travel  
pedal will cause the mower to coast to a  
(directiondependsondifferential  
stop, or resume mowing speed.  
shift position).  
Before using, disengage the cutting unit  
clutches and raise the cutting units to their  
transport position.  
Engage the clutch slowly. Refer to  
instructionsintheOPERATIONSsection  
WARNING  
NEVER USE THE TRANSPORT  
CLUTCH WHILE THE CUTTING  
WARNING  
UNITS ARE TURNING, OR WHEN THE DIFFEREN-  
TIAL SHIFT IS IN REVERSE.  
07585 – ENGINE THROTTLE  
(located on steering wheel)  
07582 - DIFFERENTIAL SHIFT LEVER  
(located on top edge of differential gear drive)  
Move the engine throttle lever forward  
forfastspeed, backwardforslowspeed  
Move the shift lever and set it in the notch to place the  
differential into Forward, Neutral, or Reverse. NEVER  
SHIFT THE DIFFERENTIAL WITH THE MOWER IN  
MOTION OR THE MAIN ENGINE CLUTCH ENGAGED.  
07586 – IGNITION KEY (Model 68 DL)  
(located on instrument cluster panel)  
07583 – WING MOWER CLUTCH  
(located on top surface of main belt  
guard)  
To start the engine, sit on the seat and  
place all cutting unit clutches in neutral.  
Turn the key to the full clockwise position  
to start the engine. Use the choke as  
required. Once the engine has started,  
release the key and allow it to rotate to the  
central run position.  
Move the clutch lever back to engage  
the wing mower clutch. Move the lever  
forward to put the clutch in neutral.  
To stop the engine, turn the key to the full  
counterclockwise position.  
Refer to the engine manual for details on proper engine  
operation.  
Disengagecuttingunitclutches, engagetheparkingbrake  
and remove the key whenever leaving the mower seat.  
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SAFETY AND CONTROL DECALS  
07587–IGNITIONKEY (Model68SR)  
(located on top surface of main belt  
guard)  
07599 – WARNING  
DECAL  
(locatedoninstrument  
cluster[68DL]ormain  
belt guard [68 SR])  
To start the engine, place the main  
clutch and all cutting unit clutches in  
neutral. Turn the key to the clockwise  
position and pull on the recoil starter.  
Use the choke as required.  
Read and understand  
the information in the  
Owner’s Manual be-  
fore operating this  
mower.  
To stop the engine, turn the key to the  
full counterclockwise position.  
Read and understand  
the information in the  
Refer to the engine manual for details on proper engine  
operation.  
Owner’s  
Manual  
before attempting to  
repair, service, or  
maintain this mower.  
Disengage cutting unit clutches, engage the parking  
brake and remove the key whenever leaving the mower  
seat.  
Turn off the mower  
engine, remove the  
ignition key, and  
disconnecttheengine  
spark plug before  
07588–PARKINGBRAKELEVER  
(locatedontopsurfaceofmainbelt  
guard)  
attempting to repair, service, or maintain this mower.  
The engine exhaust from this prod-  
WARNING  
Move the parking brake lever  
forward to set the brake, rearward  
to release the brake. Driving the  
mower with the parking brake set  
willcauseexcesswearonthebrake  
mechanism.  
uct contains chemicals known to  
thestateofCaliforniatocausecancer, birthdefects, or  
other reproductive harm. Do not operate the engine in  
a confined space where dangerous carbon monoxide  
fumes can collect.  
Objects may be thrown from the cut-  
ting units. Keep bystanders away  
from the mower.  
WARNING  
07589 – SERVICE BRAKE PEDAL  
(located on top surface of main belt  
guard)  
Never allow the mower to freewheel  
DANGER  
down hills without the traction drive  
engaged. Serious injury or death can result from loss  
of control.  
Press the brake pedal with your right  
foot to stop the mower. You must also release the main  
engine clutch in order for the mower to come to a  
complete stop.  
Do not operate the mower on slopes  
greater than 15 degrees.  
WARNING  
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07083 – SERIAL NUMBER DATA PLATE  
(located on mower frame, left side, below seat)  
07590 – REAR CUTTING UNIT CLUTCH  
(located on top surface of rear cutting unit)  
Pull lever forward and toward the center of the machine  
to engage sliding jaw clutch.  
To disengage, pull lever forward and out to engage  
locking pin.  
Never engage the drive unless the rear cutting unit has  
been lowered to the cutting position.  
(Note that the decal is viewed properly while looking  
toward the rear of the mower.)  
07600 – CUTTING UNIT DANGER  
(located on top surface of each cutting unit)  
Reels and bed knives on the cutting  
units are sharp. Keep hands and  
feet away from the cutting units.  
DANGER  
Do not attempt to work around the  
DANGER  
cutting units while they are running.  
Your fingers, hands, arms, or any loose clothing may  
become entangled in the belt drives. Do not operate  
the cutting units unless you are seated on the mower.  
Keep all guards and shields in place.  
07595 – MANUFACTURER & SOUND LEVELS  
(located on left side of main belt guard)  
Guaranteed sound power level and manufacturer’s  
information  
205341 – INSTRUCTIONS for OPTIONAL DIAL-A-  
HEIGHT ADJUSTER  
(located on the top shield of each cutting unit)  
07415 – MODEL 68 DL LABEL (68 DL only)  
07598 – MODEL 68 SR LABEL (68 SR only  
(located on left side of engine belt guard and right side of  
main belt guard)  
Raise and turn the adjuster knob counterclockwise to  
lower the height of cut. Raise and turn the adjuster knob  
clockwise to raise the height of cut. Read the instructions  
for the Dial-A-Height adjusters in the Operations section  
of this manual.  
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SAFETY AND CONTROL DECALS  
205399 – Optional DIAL-A-HEIGHT SCALE (Rear cutting  
units)  
205346–OptionalDIAL-A-HEIGHTSCALE(Wingcutting  
units)  
(located on each Dial-A-Height bracket)  
Align the bottom edge of the Dial-A-Height bracket with  
thedesiredheightofcutonthisdecal. Readtheinstructions  
for the Dial-A-Height adjusters in the Operations section  
of this manual.  
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NATIONAL 68 SR & DL TRIPLEX  
RECEIPT OF SHIPMENT  
Carefully inspect your machine and crate for damage that  
could have occurred during shipment. If damages or  
shortages are noted, have the transportation company’s  
representative note this on the bill of lading.  
Note: Claims for shipping damages must be noted by the  
consignee at the point of destination and filed with the  
transportation company that delivers the shipment.  
UNCRATING INSTRUCTIONS  
Wear protective gloves. Steel  
CAUTION  
3. Unbolt Seat (3) from crate bracing and lay seat aside  
for installation later.  
banding is sharp. Handle cutting  
units carefully. Reels rotate freely  
and are very sharp.  
4. Lift Rear Cutting Unit (4) off the crate supporting  
members and set aside for later attachment.  
5. Make sure Wing Cutting Units (5) are in their upright  
positions, secured to the mower frame with Wing  
Cutting Unit Latches.  
In order to prevent possible damage to the machine or  
personal injury, the following uncrating procedure must  
be followed:  
6. Knock down all sides of crate and remove. Roll  
mower backwards off of crate base.  
1. Position Crate (1) on a hard, level surface.  
2 Cut and remove all Steel Banding (2). Remove the  
entire top of the crate.  
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ASSEMBLY  
Improper assembly or adjustments  
can cause serious injury.  
WARNING  
SEAT  
REAR CUTTING UNIT  
1. Mount the Rear Cutting Unit Lifter and Seat Assembly  
(A) to the mower frame using (2) 1/2" bolts, nuts, and  
washers (B).  
1. Pivot the Seat Brace (A) from the axle so that the top  
end aligns with the tab at the back of the seat hinge  
assembly. Fasten with a 5/16" x 1" Hex Head Bolt,  
Lock Washer and Hex Nut.  
2. Fasten the seat slides (C) to the bottom of the seat (D)  
using the fasteners provided with the slider mecha-  
nisms. Orient the slider so the adjuster lever (E) is on  
the operator's left hand side.  
2. Slide the rod end of the lifter tee (B) through the hole  
(C) in the pad on the rear mower frame and secure it  
to the lift arm pivot with the cotter pin and washer as  
shown at (D).  
3. Remove the seat switch bracket (F, 1" x 10" bar))  
mounted near the ends of the legs of the seat hinge.  
Discard the fasteners. Mount the seat and slider as-  
sembly onto the seat hinge (G). Replace the seat  
switch bracket and tighten fasteners. Plug the wire  
harness socket (H) into the seat safety switch (J). Use  
care in routing the wires so that they are not pinched  
by the switch lever or seat support mechanisms.  
3. Attach the Pull Rod (E) to the cutting unit Pivot Tube  
(F) with Pin and Spacers.  
NOTE: Before completing assembly, it will be necessary  
to adjust the drive belt tension. See "Rear Cutting Unit  
Drive Belt Tension" in the Maintenance section of this  
manual, page 23.  
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NATIONAL 68 SR & DL TRIPLEX  
WING CUTTING UNITS  
1. Remove the two Wing Cutting Unit Belts from the  
steering column.  
2. Release the Laches (A) from Wing Cutting Units. To  
release the latch, lift the wing cutting unit handle until  
the latch swings upward into a nearly vertical position.  
Carefully lower the cutting unit to the ground. Avoid  
dropping the cutting unit, as damage may result to the  
cutting unit, the mower, or your turf.  
3. Slip wing Cutting Unit belts (B) over Countershaft  
Pulleys (C).  
4. Block mower wheels to prevent mower from moving  
forward. Pull Wing Cutting Units (D) forward so that  
they slide on Pull Rods (E) and compress springs (F).  
This will allow enough slack to enable belts to be  
installed over Reel Pulleys (G).  
5. Pull Cutting Units backwards to adjust belt tension.  
Tighten bolt (H) to lock in place.  
REEL TO BED KNIFE ADJUSTMENT  
To prevent damage during shipment, the reels have been  
moved away from the bed knives at the factory. Follow  
the procedure for "Reel to Bed Knife Adjustment" in the  
Maintenance section of this manual to properly adjust  
your cutting units.  
REAR CUTTING UNIT BELT  
Install Rear Cutting Unit Belt (A) from Countershaft Pulley  
(B) to outer Drive Pulley (C). Idler Pulley (D) must ride on  
top of lower belt to provide proper tension. NOTE: It will be  
necessary to raise rear cutting unit to allow enough slack  
to get belt over pulleys.  
ENGINE  
MOWER IS SHIPPED WITH DRY  
CAUTION  
ENGINE. DONOTSTARTENGINE  
UNTIL OIL IS ADDED TO CRANKCASE. See Engine  
Manual for additional information.  
DIFFERENTIAL  
Grease has been installed in the differential at the factory.  
For additional information, refer to the Maintenance sec-  
tion of this manual.  
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PREPARATION  
FUEL - Check fuel level. Add fuel as required. Refer to  
the engine manual for type of fuel and other safety  
requirements.  
Handle cutting units carefully with  
protective gloves. Reels and bed  
knives are very sharp. Reels rotate freely and rotating  
DANGER  
one reel can cause other reels to rotate.  
ENGINE COOLING - Keep engine cowlings clear of  
clippings.  
Movingmachinerycanbedangerous  
CAUTION  
LUBRICATION - Add lubricant to pivots and other  
lubrication points as required. Refer to the lubrication  
chart in the Maintenance section of this manual.  
if not operated properly. Follow all  
safeoperatingsuggestionslistedintheSafetyInformation  
section of this manual.  
REELS CLEAR OF DEBRIS - Remove any debris that  
may be tangled in the cutting reels. Keep the reel shaft  
and bearing clean of grass or other debris buildup.  
Checkthefollowingitemsbeforeeachuseofthemower.  
SAFETY SWITCH OPERATION - Check operation of all  
safety switches. Do not use mower if safety switches are  
disconnected or not operational, as dangerous conditions  
will result.  
TIRE PRESSURE - Use a tire pressure gage to check  
the tire pressure. Fill tires with compressed air as  
needed to obtain the pressure labelled on the sidewall of  
the tire.  
ENGINE OIL - Check level on dipstick. Refer to the  
engine manual for instructions on adding oil and which  
oil viscosity to use.  
OPERATION  
The following is a description of the machine controls  
and their function.  
The engine clutch lever has an electrical interlock and  
engine will not start if clutch is engaged. For added  
safety, the interlock system should be checked  
periodically to ensure that it is adjusted to function  
properly.  
A. Main Clutch Lever  
Engage slowly before full  
WARNING  
engagement. Always disengage  
B. Engine Throttle Lever – Regulates mowing and  
travelspeeds. Movingthecontrolhandlebackwillreduce  
enginespeedforstartingandidlingengine. Pushforward  
to increase engine speed. Never travel at speeds faster  
than required for proper mowing.  
the drive when stopping or leaving the machine.  
C. Wing Cutting Unit Clutch Lever – Engages drive to  
WingCuttingUnits.Pullleverbackanddowntoengage.  
Never engage drive unless Wing Cutting Units have  
been lowered to cutting position.  
Engages power for  
travel and mowing. Down  
position is disengaged  
and up position is  
engaged.  
Engine Choke Lever (No photo) - Located near the  
upper rear right corner of the engine. Use the choke  
when starting a cold engine. See the engine manual for  
engine starting information and proper use of the choke.  
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NATIONAL 68 SR & DL TRIPLEX  
OPERATION  
G. Rear Cutting Unit Clutch  
D. Transport Clutch (Model 68 DL only)  
Engages drive to the Rear  
Cutting Unit.  
NEVER USE THE TRANSPORT  
CLUTCH WHILE THE CUTTING  
UNITS ARE TURNING OR WHEN THE  
DIFFERENTIAL SHIFT IS IN REVERSE.  
WARNING  
Pull lever forward and  
toward the center of the  
machine to engage sliding  
jaw clutch.  
Use this clutch to travel  
between mowing sites at  
speeds faster than those  
obtained with the main  
clutch. Before using,  
disengage the cutting unit  
clutches and raise the  
cutting units to their  
transport position.  
To disengage, pull lever  
forward and out to engage  
locking pin.  
Never engage the drive  
unless the rear cutting unit  
has been lowered to the  
cutting position.  
H. Rear Cutting Unit Lift Arm  
Operate the transport clutch by slowly pressing the pedal  
with your left foot. Releasing the pedal will cause the  
mower to coast to a stop, or resume mowing speed.  
Raisesrearmowertothe  
transport position. Pull  
handle up, forward and  
over center to lock it in  
the up position.  
E. Wing Cutting Unit Latch  
NEVER ATTEMPT TO RAISE THE  
WARNING  
WING CUTTING UNITS WHEN  
THE WING MOWER CLUTCH IS  
ENGAGED.  
J. Seat Position Adjuster Lever  
DO NOT OPERATE THE SEAT  
TheWingCuttingUnitsshouldbelatchedintheirelevated  
position whenever the mower is being transported or in  
storage.  
WARNING  
SLIDE MECHANISM WHILE THE  
MOWER IS MOVING  
If needed, push the latch  
(E) down to a generally  
horizontal position. Grasp  
the Wing Cutting Unit lift  
handle (not shown) and  
raise the cutting unit until  
the latch (E) engages the  
lift arm socket (F).  
The seat may be moved forward or backward to suit the  
operator. Pull the lever near the front left corner of the  
seat outward to release the slide mechanism. After  
moving the seat to a comfortable position, release the  
lever to lock the slide mechanism.  
To release the latch, lift the handle until the latch (E)  
swingsupwardintoanearlyverticalposition,thencarefully  
lower the cutting unit onto the ground. Avoid dropping the  
cutting unit, as damage may result to the cutting unit, the  
mower, or your turf.  
.
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OPERATION  
K. Ignition Switch (Model 68 DL shown)  
M. Parking Brake Lever  
ALWAYS SHUT OFF THE ENGINE  
AND REMOVE THE KEY BEFORE  
LEAVING THE MOWER SEAT.  
CAUTION  
Provides a lock for the brake. Push brake lever forward,  
over center, to lock. Pulling brake lever back, toward the  
rear of the machine will disengage the brake.  
The 68 DL ignition  
switch is located on  
the  
instrument  
N.  
Brake  
Service  
cluster. It is a three-  
position switch.  
DepresstheSer-  
vice Brake foot  
pedal to slow the  
mower and lock  
the rear wheels  
in the full stop  
position.  
Turn  
the  
key  
clockwise to the  
middle position to  
activatetheelectrical  
system. Turnthekey  
to the full clockwise  
position to start the  
Note: It is best to  
slow the mower  
with the throttle and then disengage clutch lever before  
applying brake. This prevents excessive wear and engine  
overload.  
engine. Turn the switch counterclockwise to shut off the  
engine.  
The 68 SR ignition switch (not shown) is located on the  
steering column. It is a two-position switch.  
Turn the key clockwise to activate the electrical system  
and allow the engine to be started. Turn the switch  
counterclockwise to shut off the engine.  
SAFETY SWITCHES  
Your National 68 mower is equipped with safety switches  
to monitor the operating conditions of certain machine  
functionsandstopthemowerwheneverunsafeconditions  
are found.  
L. Differential Shift Lever  
Never shift while machine is in mo-  
WARNING  
tion, as damage to the gears could  
It is necessary for both the main engine clutch and the  
wing cutting unit clutch to be in their neutral position to  
start the engine. The 68 DL also requires the operator be  
in the seat. The 68 SR does not require the operator to be  
in the seat to facilitate use of the hand recoil starter.  
result. Always disengage engine clutch before attempt-  
ing to shift.  
Located on  
the mower  
differential,  
this control  
hasthreepo-  
sitions: For-  
ward, Neu-  
tral (center  
p o s i t i o n ) ,  
If you encounter difficulties starting the mower’s engine,  
or keeping it running, check the chart in the Safety  
Switches section of this manual to make sure you are not  
causing the engine to kill or become unable to start.  
and  
Re-  
verse. The  
levermustbe  
pulled to-  
wardthecen-  
ter of the machine to clear the notch in the stop disc and  
positioned securely in the new notch.  
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NATIONAL 68 SR & DL TRIPLEX  
2. DIAL-A-HEIGHT ADJUSTERS (OPTIONAL)  
HEIGHT OF CUT ADJUSTMENT  
To set the height of cut, lift the vinyl cap and socket (A) off  
the adjuster tube. To raise the height of cut, turn the  
socket clockwise (viewed from above). To lower the  
height of cut, turn the socket counterclockwise. Each  
quarter turn (90°) of the socket will raise or lower the  
height of cut by approximately 1/32". A full turn (360°) will  
raise or lower the height of cut approximately 1/8".  
To assure safety, disengage the  
engine clutch lever, remove the  
ignition key, and disconnect the engine spark plug  
wire prior to making any of the following adjustments.  
DANGER  
1. STANDARD ADJUSTERS  
When making large adjustments (over 1/2"), make small  
adjustments to each side until the desired change is  
reached. When the desired height is achieved, lower the  
socketandmakesuretheadjustertubelocksitinposition.  
The height of cut is variable and may be adjusted on both  
wing cutting units and the rear cutting unit by loosening  
the top and bottom Adjusting Nuts (A) which hold Roller  
Adjusters (B) in Roller Brackets (C). Roller (D) may then  
be moved up and down.  
The scale decal (C) on the rear side of the adjuster  
indicates the height of cut. To use it, sight along the  
bottom edge of the adjuster tube (B). The reading on the  
scale is your approximate height of cut.  
It is important to get all rollers adjusted to the same height  
so that there will be uniform cutting across the entire width  
of the cutting unit. Do not adjust by sight. Place the mower  
on a hard, level surface and place a board or gauge plate  
of the desired height under each bed knife back bar. Allow  
the rear roller to rest on the level surface. Retighten the  
adjusting nuts and remove the gauge plate or board.  
You should determine the exact settings by test mowing  
your turf. If very accurate cutting heights are required,  
place the cutting units on a hard, level surface and place  
a board or other gauge plate of the desired height under  
each bed knife backing bar. Lower the rollers to the level  
surface. When completed, make sure the socket is  
locked in position over the adjuster tube.  
DIAL-A-HEIGHT ADJUSTER (OPTIONAL)  
OTHER ADJUSTMENTS  
STANDARD HEIGHT ADJUSTER  
For other machine adjustments, see the Maintenance  
section of this manual.  
NOTE: Guards removed or cut away to show detail  
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MAINTENANCE  
LUBRICATION  
leakage is evident, it is recommended that the grease be  
checkedonceeachyear.Checkgreaselevelbyloosening  
the bolts in the differential case flanges and spreading  
case halves. It is not necessary to totally disassemble the  
case or remove the wheels for this inspection. Add Multi-  
purpose Gear Grease such as Pennzoil No. 303 or  
equivalent if necessary. Total grease capacity is 1-1/2  
pounds (0.68 kg).  
Lubricate the machine at the recommended locations and  
intervals using the proper lubricants to ensure maximum  
service and long life of your machine.  
Lubrication locations must be free of dirt and grass  
clippings and be well lubricated for proper operation.  
The location and number of all lubricating points are listed  
in the chart below. The type and frequency of lubrication  
is specified. Use the following photos to locate the  
lubrication points on the mower.  
Do not use oil in the differential case  
inplaceofgrease–itwillleakthrough  
the seals.  
CAUTION  
DIFFERENTIAL  
ENGINE  
Since the mower does not operate at high speeds, the  
grease level in the differential is not critical providing that  
there is sufficient grease to coat the gears. Unless  
Refer to the engine manual (separately furnished) for  
proper lubrication and maintenance instructions.  
ITEM  
1
LOCATION AND NUMBER  
Front wheel bearings (2)  
TYPE  
Grease  
Grease  
Grease  
Grease  
Oil  
FREQUENCY  
Daily  
2
Steering kingpin (2)  
25 hours  
25 hours  
25 hours  
Daily  
3
Front axle to frame pivot (2)  
Steering column (2)  
4
5
Brake pedal pivot (1)  
6
Idler pivot bracket (1 - 68 DL only)  
Main engine clutch handle (1)  
Wing mower clutch handle (1)  
Upper countershaft (1)  
Grease  
Oil  
25 hours  
Daily  
7
8
Oil  
Daily  
9
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Grease  
Daily  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
Lower countershaft (1)  
Daily  
Wing mower pull rods (4)  
Rear axle (2)  
Daily or as required  
25 hours  
25 hours  
25 hours  
25 hours  
Daily  
Input-shift tube (1)  
Brake drum tube (1)  
Main axle tube (1)  
Seat hinge (2)  
Rear mower lift arm pivot (1)  
Rear mower pivot tube (1)  
Rear mower countershaft (2)  
Rear mower clutch (2)  
25 hours  
25 hours  
Daily  
Daily  
Wing mower lift arm pin (4)  
Cutting reel bearings (6)  
Height of cutter adjuster threaded shaft (6)  
Threaded shaft and bracket (6)  
Swivel block (6)  
25 hours  
Daily  
Yearly or as required  
Yearly or as required  
Yearly or as required  
Daily  
Belt clutch idler arm (68 DL only)  
Transport clutch foot pedal (68 DL only)  
Daily  
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NATIONAL 68 SR & DL TRIPLEX  
LUBRICATION POINTS  
9. Upper countershaft  
1. Front wheel bearing  
2. Steering Kingpin  
10. Lower countershaft  
3. Front axle pivot  
4. Steering column (2 places)  
5. Brake pedal pivot  
6. Idler pivot bracket (68 DL only)  
7. Main clutch handle  
11. Wing mower pull rod (2 places)  
8. Wing mower clutch handle  
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MAINTENANCE  
LUBRICATION POINTS  
18. Rear mower pivot tube  
12. Rear axle (2 places)  
13. Differential input tube  
14. Brake drum tube  
15. Main axle tube  
19. Rear mower countershaft (2 places)  
20. Rear mower clutch  
16. Seat Hinge  
21. Wing mower lift arm (2 places)  
17. Rear mower lift arm pivot  
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NATIONAL 68 SR & DL TRIPLEX  
LUBRICATION POINTS  
22. Cutting reel bearing (6 places)  
23. Height of cut adjuster (6 places)  
Dial-A-Height adjusters (optional)  
24. Threaded shaft (6 places)  
25. Swivel block (6 places)  
Belt clutch arm pivot arms (68 DL only)  
26. Belt clutch idler arm  
27. Transport clutch foot pedal  
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MAINTENANCE  
To assure safety, disengage the  
engine clutch lever, remove the  
ignition key, and disconnect the engine spark plug  
wire prior to making any of the following adjustments.  
Do not adjust one side more than the other unless the reel  
is obviously out of alignment. Do not get the reel so tight  
that it is hard to turn by hand. A too tight reel will wear  
faster.  
DANGER  
Ideally, the reel should “wipe” or lightly touch the bed  
knife. It is not necessary to adjust or change the position  
of the lower adjustment nut.  
Handle reel assemblies carefully  
DANGER  
with protective gloves. Reels are  
very sharp. Reels rotate freely and rotating one reel  
cancauseotherreelstorotate. Specialcareshouldbe  
taken in the area where the reel contacts the bed knife.  
Proper cutting action may be tested by holding paper  
strips between the reel and the bed knife. Turn the reel by  
hand and check to see if the assembly cuts the paper all  
the way across the width of the bed knife. Make sure that  
the adjusting and the locking nuts on both side are  
tightened securely.  
REEL TO BED KNIFE ADJUSTMENT  
The reel is adjusted to a fixed position bed knife. This  
construction allows a more rugged and durable frame and  
retains the proper adjustment longer. The Reel Adjuster  
Bolt (A) regulates reel distance from the bed knife.  
REEL END PLAY ADJUSTMENT  
Test for end play periodically by trying to move the reel  
from side to side in the frame. If there is ANY movement,  
adjust the bearings by loosening the lock nut on the  
adjustmentbolt(B)whichislocatedontheinsiderightend  
of the reels, and turning the adjustment bolt IN one half  
turn or less. Do not overtighten. An overtightened bearing  
will cause excessive bearing wear. Test again for end  
play and if reel is rotating freely and end play is not  
noticeable, tighten the lock nut.  
To reduce the distance, turn the upper hex adjuster nut on  
each side of the reel down. Proceed slowly and do not  
over-adjust -- use about 1/8 of a turn on each side at first.  
HEIGHT OF CUT ADJUSTMENT  
Refer to "Height of Cut Adjustment" in the Operation  
section of this manual.  
BRAKE ADJUSTMENT  
The foot brake is properly adjusted if it slows the machine  
when depressed and can be locked when the pedal is  
depressed fully.  
Adjust brake tension by removing cotter pin and brake  
pedal pin and turning brake clevis located under pedal on  
brake rod. When adjustment is complete, attach clevis to  
pedal with pin and cotter pin.  
REEL ADJUSTMENTS  
NOTE: Guards removed or cut away to show detail  
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ADJUSTING DRIVE BELT TENSION  
A belt adjusted for proper tension can be deflected slightly  
at a point midway between the pulleys. An over-tight belt  
will cause excessive bearing wear and an under-tight belt  
allows slipping, causing excessive belt wear.  
IMPORTANT: Never allow oil to get on the belt which  
could cause slipping.  
WING CUTTING UNIT DRIVE BELT TENSION  
Adjust tension by loosening set screw (B) in the wing  
mower pull arm, sliding the Cutting Unit rearward and  
retightening set screw.  
MAIN DRIVE BELT TENSION (Main Countershaft to  
Rear Drive)  
Belt tension is increased by loosening the four bolts  
holding the Upper Countershaft Housing (A) and sliding  
the housing forward in the slotted frame holes.  
NOTE-Itwillbenecessarytoremovebeltguardstoreach  
the adjustment bolts. Also, if this belt is adjusted, it will be  
necessary to readjust the engine belt. Replace all belt  
guards before using the mower.  
FRONT  
OF  
MACHINE  
ENGINE DRIVE BELT TENSION (Engine to Main  
Countershaft) (No photo)  
Belt tension is increased by loosening the four engine  
mounting bolts and sliding the engine forward in the  
slottedframeholes.Testforthepropertensionasdetailed  
in the section "Wing Cutting Unit Drive Belt Tension".  
When tension is correct, tighten all the bolts securely.  
REAR CUTTING UNIT DRIVE BELT TENSION  
Spacers (A) are provided on the rear mower Pull Rod (B)  
to adjust the belt tension. Remove Pin (C) from the end of  
the pull rod and slip out the pull rod from the Pivot Tube  
(D). Move as many spacers as necessary to the location  
indicated and reassemble.  
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MAINTENANCE  
BED KNIFE REPLACEMENT  
Reelsandbedknifearesharp. Wear  
REAR CUTTING UNIT CHAIN TENSION  
A chain drive is located on the left side of the rear cutting  
unit. It maybe helpful to remove the Chain Shield (A) prior  
to adjusting the chain tension.  
DANGER  
gloves to avoid cutting fingers on  
sharp edges. Wear safety glasses  
to protect eyes.  
Adjust the tension of the chain by loosening the 4 bolts (B)  
on the rear cutting unit countershaft housing. Rotate the  
countershaft housing (C) about the pivot line created by  
the fixed bolts. The slots on the countershaft housing will  
slideovertheremainingtwobolts. Rotatethecountershaft  
housing until proper chain tension is achieved. Tighten  
bolts.  
When the bed knife becomes damaged or too worn to  
keep sharp, it must be replaced. Follow the procedure  
below.  
1. Thebackbar(A),bedknife(B)andfasteners(C,D)have  
been assembled at the factory under tension. To ease  
replacement and prevent misalignment of compo-  
nents, you may wish to clamp the leading edge of the  
backbar in two or three places before removing the old  
fasteners.  
Proper tension is achieved when the chain is slightly  
loose, but does not deflect more than 1/2" when pressed  
in the middle of the span between the two sprockets.  
2. Remove the old shoulder nuts (C) and flat head screws  
(D). If shoulder nuts are badly rusted or corroded, they  
may have to be cut off and screws driven out to be  
removed.  
3. Clean the bottom surface of the backbar for maximum  
metal contact with the new bed bar.  
4. Fasten the new bed knife to the bottom of the backbar  
in the position shown (bent edge up). Shoulder of  
shoulder nuts (C) must be seated firmly in the backbar  
andscrews(D)mustbeflushwiththebottomofthebed  
knife.  
5. Torque shoulder nuts 35 to 40 ft-lbs.  
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NATIONAL 68 SR & DL TRIPLEX  
BACK LAPPING PROCEDURE  
BACK GRIND IN THE  
DIRECTION  
OF THE ARROW  
Be extremely careful not to let the  
brush, your fingers or your clothing  
get caught in the reels. Wear gloves to avoid cutting  
fingersonsharpedges. Wearapprovedsafetyglasses  
toprotectyoureyesfromflyingparticlesandabrasives.  
DANGER  
INTRODUCTION  
Back lapping is a very important step in maintaining sharp  
reel blades on the cutting units.  
25O  
Thisprocedureshouldbeperformedwhenthereelblades  
and the bed knife become slightly rounded and the grass  
is not cut cleanly with only a slight reel to bed knife  
adjustment. Also, after grinding the bed knife and reels,  
you should back lap to establish a perfect match between  
the bed knife and reel blades.  
Note position of  
blades to reel  
axis  
RECOMMENDED STEPS  
1. Adjust the reel to the bed knife so that the bed knife is  
parallel to the reel and light contact is maintained.  
GRINDING REELS  
Reels must be ground at 25° in the direction shown by the  
arrow in the figure. Back grind until reel blades are free  
from roundness, dents and nicks. Spin grind to remove all  
burrs. All blades must be on the same diameter.  
2. Reels must be run in a reverse direction to be lapped.  
Remove the lower drive belts and attach a back  
lapping machine (not supplied by National Mower) to  
the reels. Follow the instructions furnished by the  
machine manufacturer.  
3. Apply the lapping compound with the reels running,  
using a 2" or a 3" (5 - 7.5 cm) brush. Apply the  
compound evenly to the moving blades.  
5O  
Many types of compounds are available for lapping. We  
recommend a good pre-mixed water soluble compound.  
Pre-mixed compound saves the time required to mix,  
eliminates the waste of abrasive, rinses off easily with  
water and is available in all grit ranges from coarse to  
extra fine.  
5O  
GRINDING BED KNIVES  
4. Stop the reel and examine both bed knife and reel  
blades to see that the cutting edges are uniformly  
sharp. If not, gradually tighten the reel adjuster bolts  
(see "Reel to Bed Knife Adjustment" above) and  
repeat Step 3 until the proper sharpness results.  
For maximum cutting efficiency, grind bed knife top and  
front edges at 5° as shown in the figure.  
5. Rinse off the compound thoroughly with water to  
removeallabrasive.Checkforsharpnessandreadjust  
the bed knife if necessary. Reel to bed knife contact  
should be adjusted to easily cut a sheet of paper (see  
"Reel to Bed Knife Adjustment" above).  
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MAINTENANCE RECORD  
Date  
Maintenance Task  
Person  
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TROUBLE-SHOOTING  
All adjusting must be made with the engine off.  
Do not do any investigation of the working parts of the machine with the motor running.  
Always turn the engine off!  
DANGER  
Tractor Unit  
Situation  
Things To Check  
Engine will not start  
Turn ignition switch to on  
Ensure that there is sufficient gasoline (petrol) in the tank  
Make sure safety switches are making contact and mowing clutch is in  
neutral  
Look for a loose wire on ignition or spark plug wire not connected  
Interlock system inoperative—check wiring, see "Electrical Diagrams"  
Operator must be positioned on seat to depress safety switches  
(Model 68 DL only)  
Mower will not move  
Differential gear selector must be in one of the drive positions  
Engine drive clutch must be engaged  
Drive belts too loose (see "Drive Belt Tension" in Maintenance section)  
Visually check to see that pulleys are not slipping on shafts  
If everything above is OK, check for a damaged gear(s) in the differential  
gear box  
Mower will not stop  
Ensure that the main clutch is disengaged (brake will not stop engine)  
Brake adjustment or service may be needed.  
Cutting Units  
Situation  
Things To Check  
Cutting units will not turn.  
Clutches may not be engaged  
Look for anything that could be jammed between the reel and the bed knife  
Drive belts or drive chain may need tightening  
Visually check that both the drive pulleys and the shafts are rotating  
Cutting units turn but  
will not cut  
Reel bed knife position may be out of adjustment (see "Reel to Bed Knife  
Adjustment" in Maintenance section)  
Drive belts or drive chain may need adjustment.  
Visually check that both the drive pulleys and the shafts are rotating  
Cutting units will not stop  
turning  
Disengage all clutches  
Uneven cut  
Set height of cut to the same height on each cutting unit (see "Cutting Height  
Adjustment" in Operation section of this manual.)  
Check to see if any part is bent  
Something may be jammed in cutting unit pivots and/or lift pivots, preventing  
the cutting units from floating  
27  
68OM-06/03  
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PARTS LIST  
FRAME & RUNNING GEAR  
28  
68OM-06/03  
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®
NATIONAL 68 SR & DL TRIPLEX  
FRAME & RUNNING GEAR  
Item  
Part No.  
Description  
Qty.  
1
2
200002  
07018  
FRAME  
1
2
REAR TIRE & WHEEL ASSEMBLY  
3
4
5
200085  
201961  
06002  
FOOT REST, Left Hand  
BUSHING, Axle Pivot  
BUSHING, Spindle and Steering Post  
____________________________________________________________________________________________________________________________________1____  
2
6
6
7
8
_____________________0__9_0__1_4____________________________________________________________________________________________________________  
DRAG LINK  
KING PIN, Left Hand  
1
200193  
07038  
1
2
TIRE & WHEEL  
SHAFT, Steering  
AXLE ASSEMBLY, Front  
TIE ROD  
9
10  
11  
200094  
201427  
201851  
____________________________________________________________________________________________________________________________________1____  
1
1
12  
04003  
_________________________________________________P__I_N__,_C__le__v_i_s__T_i_e__R__o_d________________________________________________________________________  
1
13  
14  
200196  
200033  
KING PIN, Right Hand  
BUMPER, Front  
1
1
15  
06112  
BEARING, Wheel Hub  
4
____________________________________________________________________________________________________________________________________________  
16  
02602  
02603  
200863  
200104  
200139  
DUST CAP, 3/4'’ I.D.  
DUST CAP, 7/8'’ I.D.  
2
2
1
1
1
17  
18  
19  
_________________________________________________C__L__E_V__I_S_,__T_h__r_e_a__d_e_d__,_T__i_e__R__o_d______________________________________________________________  
PEDAL, Brake  
FOOT REST, Right Hand  
___2_0__________________0__7_5__6_0_________________________________________________________________________________________________________________  
SWITCH, Interlock  
GUARD, Main Belt  
STEERING WHEEL  
1
1
1
21  
22  
09217  
200200  
23  
200199  
COLLAR, Steering Shaft  
1
________________________________________________________________________________________________________________________________________________  
24  
25  
200203  
07034  
BRACKET, Throttle Control  
SWITCH, Key, Briggs & Stratton and Kawasaki  
1
1
___2_6__________________0__7_0__3_2_________________________________________________________________________________________________________________  
THROTTLE CONTROL, (Includes conduit and wiring)  
SEAT  
BALL JOINT  
1
1
2
27  
28  
07036  
200867  
29  
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RUNNING GEAR & MISC. PARTS -- MODEL 68 DL  
Item  
Part No.  
Description  
Qty.  
1
2
07065  
07064  
KEY SWITCH  
AMPMETER  
1
1
3
07063  
HOURMETER  
1
____________________________________________________________________________________________________  
4
5
09098  
09218  
DASHBOARD  
GUARD, Main Belt  
1
1
6
200200  
STEERING WHEEL  
1
____________________________________________________________________________________________________  
7
8
09101  
201754  
COVER, Battery  
HOLDOWN, Battery  
1
1
9
201582  
BATTERY BOX  
1
____________________________________________________________________________________________________  
10  
11  
202447  
201925  
ROD, Side Post Battery  
FOOT REST, Left  
2
1
12  
13  
07038  
07560  
TIRE, Deluxe Wide  
INTERLOCK  
2
1
____________________________________________________________________________________________________  
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®
NATIONAL 68 SR & DL TRIPLEX  
SEAT MOUNTING & BELT GUARDS  
Item  
Part No.  
Description  
Qty.  
1
2
07101  
200814  
ADJUSTER, Seat  
HINGE, Seat  
1
2
3
205470  
BRACKET, Seat Switch  
1
_________________________________________________________________________________________________________________________________________  
4
5
02614  
04512  
WASHER  
SPRING, Seat  
2
2
6
202249  
TUBE, Pivot  
1
_________________________________________________________________________________________________________________________________________  
7
8
202251  
07039  
HANDLE, Lifter  
GRIP, Handle  
1
1
9
09218  
GUARD, Main Belt (DL only)  
1
_________________________________________________________________________________________________________________________________________  
09217  
09213  
09216  
GUARD, Main Belt (SR only)  
SHIELD, Latch Hook, L.H.  
GUARD, Pulley (DL only)  
1
1
1
10  
11  
_________________________________________________________________________________________________________________________________________  
12  
09100  
09002  
GUARD, Engine Clutch (DL only)  
GUARD, Engine Clutch (SR only)  
1
1
13  
205485  
GUARD, Pulley  
1
_________________________________________________________________________________________________________________________________________  
14  
15  
09220  
202343  
SHIELD, Latch Hook, R.H.  
ASSEMBLY, Seat Bracket  
1
1
16  
07325  
SWITCH  
1
_________________________________________________________________________________________________________________________________________  
17  
18  
205459  
202798  
PIVOT, Switch  
SPRING, Return  
1
1
19  
20  
205460  
200123  
ARM, Spring  
BUSHING  
1
1
_________________________________________________________________________________________________________________________________________  
31  
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DRIVE MECHANISM -- UPPER PORTION  
32  
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®
NATIONAL 68 SR & DL TRIPLEX  
DRIVE MECHANISM -- UPPER PORTION  
Qty.  
Part No.  
Item  
Description  
1
2
3
4
5
6
7
8
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
200530  
03607  
03608  
200179  
200176  
200172  
200173  
202445  
201541  
201538  
200165  
08021  
202437  
200162  
03609  
03903  
200208  
200184  
04501  
200163  
07024  
09002  
03606  
200157  
03902  
04013  
02602  
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
GUIDE, Belt, High Speed Pulley  
PULLEY, Countershaft Idler  
IDLER, Engine Clutch  
ARM, Engine Clutch  
ARM, Countershaft Idler  
ROD, Countershaft Idler Control  
BRACKET, Idler Pivot  
STUD, Belt Guide  
BELT GUIDE, Lower  
BELT GUIDE, Upper  
ROD, Main Clutch, Upper  
ROD, Main Clutch, Lower  
SPRING  
COLLAR, Lock  
PULLEY, Motor  
BELT, Engine, Kawasaki, 6844 Gates Rated  
KEY, Square, Engine  
ARM, Main Belt Idler  
SPRING, Main Belt Idler Arm  
LEVER, Engine Clutch  
KNOB, Clutch Lever  
GUARD, Engine Clutch  
PULLEY, Main Countershaft  
COUNTERSHAFT, Main  
BELT, Drive, B66  
KEY, Woodruff, #11  
DUST CAP, 3/4" I.D.  
______________________________________________________________________________  
______________________________________________________________________________  
______________________________________________________________________________  
______________________________________________________________________________  
______________________________________________________________________________  
______________________________________________________________________________  
______________________________________________________________________________  
______________________________________________________________________________  
25  
26  
27  
28  
29  
30  
1
1
2
2
1
1
______________________________________________________________________________  
06006  
200154  
200158  
BUSHING, Main Countershaft Housing  
HOUSING, Main Countershaft  
STEP PULLEY, Main Countershaft  
______________________________________________________________________________  
31  
03901  
1
BELT, Countershaft, A29  
______________________________________________________________________________  
33  
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DRIVE MECHANISM -- MIDDLE PORTION  
Item  
Part No.  
Description  
Qty.  
1
2
3
SHIELD, Engine  
GRIP, Lever, '96 and up  
203622  
07023  
205486  
1
1
LEVER, Lower Countershaft Control  
_____________________________________________________________________________________________________________________________1___________  
4
5
6
SWITCH, Control  
U-NUT, 1/4-20  
07325  
02288  
205471  
2
2
BRACKET, Muffler Guard, L.H.  
____________________________________________________________________________________________________________________________1___________  
7
8
9
BRACKET, Muffler Guard, R.H.  
GUARD, Muffler  
205472  
205477  
200172  
1
1
ROD, Countershaft Idler Control (shown for reference only)  
_____________________________________________________________________________________________________________________________1___________  
10  
11  
12  
SPRING  
202437  
200182  
200170  
2
2
1
COLLAR, Lock  
ROD  
______________________________________________________________________________________________________________________________________________  
13  
14  
15  
SPRING, Lift Latch  
BUSHING  
04552  
200676  
2
4
2
HOOK, Wing Mower  
___________________2__0_5_4__5_1__________________________________________________________________________________________________________________  
16  
ROLL PIN, 0.25 x 1.12  
04056  
2
34  
68OM-06/03  
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®
NATIONAL 68 SR & DL TRIPLEX  
DRIVE MECHANISM -- LOWER PORTION  
Qty.  
Part No.  
Item  
Description  
1
2
3
03615  
06105  
205482  
2
2
1
PULLEY, Lower Countershaft  
BEARING, Lower Countershaft  
CARRIER, Lower Countershaft (Model 68SR only)  
________________________________________________________________________________________________________________________________________  
205481  
04056  
02614  
1
2
CARRIER, Lower Countershaft (Model 68DL only)  
ROLL PIN, 0.25 x 1.12  
4
5
1
_______________________________________W__A__S__H_E__R_______________________________________________________________________________________  
6
7
8
205458  
200123  
02614  
1
1
1
PIVOT, Switch, R.H.  
BUSHING  
WASHER  
________________________________________________________________________________________________________________________________________  
9
10  
11  
202798  
200137  
205461  
2
1
SPRING  
PULL ANGLE, Wing Mower, Rear  
1
_________________________________________P__I_V_O__T__,_S__w__it_c_h_,__L_._H__._______________________________________________________________________________  
12  
13  
14  
02602  
205454  
2
1
DUST CAP, 3/4" I.D.  
PULL ARM, Wing Mower, Left and Right Hand  
GRIP, Wing Mower Arm  
07226  
___________________________________________________________________________________________________________________________________1_________  
15  
16  
17  
200135  
03901  
03603  
1
1
COUNTERSHAFT, Lower  
BELT, Countershaft, A29  
1
_________________________________________P__U__L_L_E__Y__,_L__o_w__e_r__C_o__u_n__te__rs__h_a_f_t__D_r_i_v_e_______________________________________________________________  
18  
19  
20  
200136  
205462  
1
2
BELT GUIDE, Pulley  
BRACKET, Switch Mounting  
SWITCH, Control  
07325  
____________________________________________________________________________________________________________________________________2_________  
21  
22  
23  
04505  
200151  
201880  
1
1
1
SPRING, Wing Mower Pull Rod  
PULL ROD, Wing Mower  
PIN, Wing Mower Arm  
35  
68OM-06/03  
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DRIVE MECHANISM -- MODEL 68 DL  
36  
68OM-06/03  
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®
NATIONAL 68 SR & DL TRIPLEX  
DRIVE MECHANISM -- MODEL 68 DL  
Item  
Part No.  
Description  
Qty.  
1
2
09100  
201881  
201884  
201890  
201872  
GUARD, Engine Clutch  
1
1
1
1
1
RETAINER, Mowing Belt  
RETAINER, Transport Belt  
MOUNT, Belt Guides  
____3_____________________________________________________________________________________________________________________________________  
4
5
STEP PULLEY, Main Countershaft  
____6_____________________________________________________________________________________________________________________________________  
03603  
02507  
03502  
06101  
03902  
03655  
PULLEY, Transport, Main Countershaft  
Washer, 10 GA.  
O-RING, 7/8" Dia.  
NEEDLE BEARING  
BELT, Drive, B66  
1
2
2
7
8
____9_____________________________________________________________________________________________________________________________________  
2
10  
11  
12  
13  
14  
1
PULLEY, Main Countershaft  
1
3
1
1
04013  
________________________________________________K__E__Y_,__W__o__o_d__r_u_f_f_,_#__1_1___________________________________________________________________  
201871  
201740  
COUNTERSHAFT, Main  
HOUSING, Main Countershaft  
15  
200208  
________________________________________________K__E__Y_,__S__q_u__a_r_e__,_E__n__g_i_n_e_________________________________________________________________  
2
16  
17  
03926  
03602  
03903  
BELT, Engine, Transport, 6841 Gates Power Rated  
PULLEY, Engine, Transport Belt  
1
1
1
1
1
18  
19  
20  
________________________________________________B__E__L_T__,_E__n_g__i_n_e__,_M__o__w__in__g__,_6__8_4__4__G__a__te__s__P__o_w__e__r_R__a__t_e_d_______________________________  
03609  
PULLEY, Engine, Mower Belt  
BELT GUIDE WELDMENT, Engine  
STUD, Belt Guide  
BRACKET, Idler Pivot with Bushings  
GUIDE, Belt  
202780  
202446  
201946  
200530  
21  
22  
23  
_____________________________________________________________________________________________________________________________________1____  
1
1
2
4
202441  
SPRING, Transport Pedal Return  
1
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
25  
26  
27  
28  
29  
03608  
201721  
PULLEY, Idler  
FOOT LEVER  
ARM, Idler, Lower Countershaft  
ARM., Idler, Mowing Belt  
PULLEY, Clutch Lever  
1
1
201728  
201730  
03607  
_____________________________________________________________________________________________________________________________________1____  
1
1
30  
31  
32  
33  
34  
35  
201718  
201889  
201919  
________________________________________________P__U__L__L_E__Y__L__E__V__E_R__,__T__ra__n_s__p_o__r_t________________________________________________________  
1
1
1
GUIDE, Belt  
ROD, Transport Clutch  
SPRING, Transport  
202440  
201966  
205481  
_____________________________________________________________________________________________________________________________________1____  
PEDAL, Transport  
CARRIER, Lower Countershaft  
1
1
_________________________________________________________________________________________________________________________________________  
37  
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38  
68OM-06/03  
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®
NATIONAL 68 SR & DL TRIPLEX  
39  
68OM-06/03  
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WING CUTTING UNITS  
NOTE — Skids and Reel End Shields are not shown.  
See parts page "Skids, Reel End Shields & Guards"  
40  
68OM-06/03  
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®
NATIONAL 68 SR & DL TRIPLEX  
WING CUTTING UNITS  
Item  
Part No.  
Description  
Qty.  
1
2
201513  
BRACKET, Shield  
UPRIGHT, Shield  
ROLLER, 21"  
ROLLER BRACKET, L.H.  
ADJUSTER, Roller  
4
4
2
2
4
200235  
204497  
203248  
204495  
__3________________________________________________________________________________________________________________________________  
4
5
__6________________________________________________________________________________________________________________________________  
02109 SCREW, Flat Head 14  
201802 NUT, Bed Knife Screw 14  
__8_________________2_0__1_5_0__4__________________B_E__D__K__N_I_F_E__,_2__1_"_,_____________________________________________________________________  
04549 SPRING, Reel Adjusting  
200236 REEL TAKE-UP ASSEMBLY  
302550 REEL CARRIER ASSEMBLY, Left Hand  
201775  
FRAME, Bed Knife, Bolt-on  
2
7
2
9
2
10  
4
11  
2
__________________________________________________________________________________________________________________________________  
12  
13  
06120  
200296  
BEARING, Reel, (Includes Race)  
REEL ASSEMBLY, 6 Blade  
4
2
14  
201781  
FRAME, Wing Mower  
2
__________________________________________________________________________________________________________________________________  
15  
16  
200256  
201437  
ADJUSTING SCREW & NUT, Bearing  
TAKE-UP WASHER, Reel Bearing  
2
2
17  
201383  
CAP SCREW (Special), Pulley Scraper  
2
__________________________________________________________________________________________________________________________________  
18  
19  
200287  
302549  
PULLEY SCRAPER  
REEL CARRIER ASSEMBLY, Right Hand  
2
2
20  
03931  
BELT, Wing Cutting Unit (Gates A34)  
2
__________________________________________________________________________________________________________________________________  
21  
22  
03601  
201520  
PULLEY  
SHIELD, Right Hand  
2
1
201521  
SHIELD, Left Hand  
1
__________________________________________________________________________________________________________________________________  
23  
202261  
202260  
203172  
SHIELD, Belt, L.H.  
SHIELD, Belt, R.H.  
ROLLER BRACKET, R.H.  
1
1
2
24  
41  
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42  
68OM-06/03  
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®
NATIONAL 68 SR & DL TRIPLEX  
43  
68OM-06/03  
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SKIDS, REEL END SHIELDS & GUARDS  
Item  
Part No.  
Description  
Qty.  
1
2
203728  
202959  
SKID BAR, L.H.  
SHIELD, Wing Mower  
1
3
3
201585  
SKID, Mower  
2
_________________________________________________________________________________________________________________________________________________  
4
5
6
203727  
202410  
202281  
SKID BAR, R.H.  
GUARD, Inside, Rear Mower  
CHAIN GUARD, Rear Mower  
2
1
1
44  
68OM-06/03  
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®
NATIONAL 68 SR & DL TRIPLEX  
ROLLERS & STANDARD SCRAPERS  
ROLLER ASSEMBLY (21") P/N 204497 (includes items 1-4)  
ROLLER ASSEMBLY (30") P/N 204499 (Includes items 1-4)  
ROLLER SCRAPER KIT P/N 860032 (includes items 5-8)  
Item  
Part No.  
Description  
Qty.  
1
2
205330  
06142  
CAP, Bearing  
BEARING, Roller  
2
2
3
204500  
SHAFT, Roller (21")  
1
_______________________________________________________________________________________________________  
204499  
204502  
SHAFT, Roller (30")  
WELDMENT, Roller (21")  
1
1
4
204501  
WELDMENT, Roller (30")  
1
_______________________________________________________________________________________________________  
5
6
02228  
205375  
NUT, Jam, 5/16-24  
BRACKET, Roller Scraper, L.H.  
12  
3
7
09092  
CABLE, Roller Scraper (21")  
2
_______________________________________________________________________________________________________  
09090  
205376  
CABLE, Roller Scraper (30")  
BRACKET, Roller Scraper, R.H.  
1
3
8
9
204495  
ADJUSTER, Roller (not included)  
-
_______________________________________________________________________________________________________  
45  
68OM-06/03  
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DIAL-A-HEIGHT™ ROLLER SCRAPER KIT, P/N 860033 (includes items 1-4)  
Item  
Part No.  
Description  
Qty. per Kit  
1
2
205384  
04107  
BRACKET, Cable Mounting, L.H.  
U-BOLT, 1/4-20 x 1.25 ID x 2.25  
3
6
3
09092  
CABLE, Roller Scraper, Wing Cutting Unit  
2
_______________________________________________________________________________________________________  
09090  
205385  
CABLE, Roller Scraper, Rear Cutting Unit  
BRACKET, Cable Mounting, R.H.  
1
3
4
46  
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®
NATIONAL 68 SR & DL TRIPLEX  
DIAL-A-HEIGHT™ ROLLER ADJUSTER KIT, P/N 860034  
Item  
Part No.  
Description  
Qty. per Kit  
1
2
205341  
205348  
DECAL, Instruction  
ASSEMBLY, Roller Adjuster, L.H.  
6
3
3
205380  
WELDMENT, Roller Bracket, L.H.  
3
_______________________________________________________________________________________________________  
4
5
204991  
205346  
PLATE, Scale  
DECAL, Wing Cutting Unit  
6
4
205339  
DECAL, Rear Cutting Unit  
2
_______________________________________________________________________________________________________  
205381  
205349  
WELDMENT, Roller Bracket, R.H.  
ASSEMBLY, Roller Adjuster, L.H.  
3
3
6
7
_______________________________________________________________________________________________________  
47  
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DIAL-A-HEIGHT™ ADJUSTER, P/N 205348 & 205349  
Item  
Part No.  
Description  
Qty.  
1
2
204996  
205334  
CAP, Vinyl  
WELDMENT, Threaded Rod  
1
1
3
204995  
SPRING  
1
_______________________________________________________________________________________________________  
4
5
205345  
205399  
WELDMENT, Socket  
WELDMENT, Height of Cut Adjuster, R.H.  
1
1
205400  
WELDMENT, Height of Cut Adjuster, L.H.  
1
_______________________________________________________________________________________________________  
6
204997 END, Swivel  
1
_______________________________________________________________________________________________________  
48  
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®
NATIONAL 68 SR & DL TRIPLEX  
SAFETY SWITCHES  
If you encounter difficulties starting the mower’s engine,  
or keeping it running, check the chart below to make sure  
you are not causing the engine to kill or become unable  
to start.  
Never attempt to remove or  
circumvent the safety switches.  
DANGER  
Dangerous operating conditions may result.  
Your National 68 mower is equipped with safety switches  
to monitor the operating conditions of certain machine  
functionsandstopthemowerwheneverunsafeconditions  
are found.  
With the engine off, and the ignition key removed, check  
theswitchesregularlytomakesuretheyareunobstructed  
by grass clippings or other material. Make sure the  
electrical terminals remain clean and dry and the pivot  
mechanisms for each switch operate freely.  
It is necessary for both the main engine clutch and the  
wing cutting unit clutch to be in their neutral position to  
start the engine. The 68 DL also requires the operator be  
in the seat. The 68 SR does not require the operator to be  
in the seat to facilitate use of the hand recoil starter.  
Never spray the mower safety switches directly with high-  
pressure water.  
Seat Switch Wing Cutting  
68 DL  
Engine  
Response  
68 SL  
Engine  
Response  
Main Engine Wing Cutting  
(Operator  
Presence)  
Unit Lift  
Arms  
Clutch  
Unit Clutch  
ENGAGED  
ENGAGED  
OFF  
ON  
DOWN  
UP  
KILL  
KILL  
RUN  
KILL  
KILL  
KILL  
RUN  
RUN  
RUN  
KILL  
RUN  
KILL  
KILL  
KILL  
RUN  
KILL  
KILL  
KILL  
RUN  
RUN  
KILL  
KILL  
RUN  
KILL  
DOWN  
UP  
NEUTRAL  
OFF  
ON  
DOWN  
UP  
DOWN  
UP  
NEUTRAL  
ENGAGED  
OFF  
ON  
DOWN  
UP  
DOWN  
UP  
START &  
RUN  
NEUTRAL  
OFF  
ON  
DOWN  
UP  
RUN  
RUN  
START &  
RUN  
START &  
RUN  
START &  
RUN  
DOWN  
UP  
START &  
RUN  
START &  
RUN  
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ELECTRICAL DIAGRAMS  
MODEL 68 SR ELECTRICAL -- SAFETY SWITCH AND CIRCUIT DIAGRAM  
MODEL 68 DL ELECTRICAL -- SAFETY SWITCH AND CIRCUIT DIAGRAM  
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®
NATIONAL 68 SR & DL TRIPLEX  
ELECTRICAL P  
ARTS-- MODELS 68 SR & 68 DL  
Part No.  
Qty.  
Description  
Model 68 SR  
Model 68 DL  
07034  
07065  
07063  
07064  
KEY SWITCH  
HOURMETER  
1
1
*
_________________________________________________A__M__P__M__E_T__E_R__________________________________________________________________  
1
_________  
BATTERY (Exide GT-H or equiv  
GROUND WIRE, Battery  
., 12V, U1, 235 CCA @ 0°F)  
1
1
07104  
07570  
_______________________0__7_5_8__0__________________________________________________________________________________________________  
HARNESS ASSEMBL  
Y
1
________  
07325  
07560  
07325  
SWITCH, Safety  
INTERLOCK MODULE  
5
1
_______________________________________________________________________________________________________________________________  
__________  
*Note: Your mower may be equipped with a digital hour meter. This meter will  
display a signal after 5 hours, and every 25 hours thereafter, recommending that  
you change the engine oil and lubricate the mower.  
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SPECIFICATIONS  
MOWER DIMENSIONS & WEIGHT  
Overall Length.............................................................................................. 79.13" (201 cm)  
Width, Wing Mowers Folded .......................................................................... 61.8" (157 cm)  
Width, Wing Mowers Down ............................................................................... 76" (193 cm)  
Height ............................................................................................................ 39.37"(100 cm)  
Weight (empty)............................................................................................ 659 lbs. (299 kg)  
ENGINE – BRIGGS & STRATTON 138400 SERIES  
Engine Type .............................. Forced Air Cooled, 4-cycle, Horizontal Shaft, OHV Engine  
Number Of Cylinders ...................................................................................................... One  
Piston Displacement .............................................................................. 13.1 cu. in. (215 cc)  
Maximum Horsepower .................. 7.5 hp (5.6 kW)) / 3600 rpm (Corrected per SAE J1349)  
Direction Of Rotation............................... Counterclockwise, facing the power take-off shaft  
Maximum Speed ........................................................................................... 3600 ±100 rpm  
Fuel ............................................................................................ Unleaded Gasoline (Petrol)  
Fuel Tank Capacity ............................................................................... 4.80 US qt (4.5 liter)  
Maximum Fuel Consumption ............................................................ 0.68 gal/hr (2.4 liter/hr)  
Oil ........................................................................................................... SAE 30 Engine Oil  
Oil Capacity ............................................................................................. 30 fl. oz. (0.90 liter)  
Carburetor ............................................................................. Float Type with Fixed Main Jet  
Starter (68 SR) .................................... Recoil Starter with Automatic Compression Release  
Starter (68 DL) ................................................................. Electric Starter and Recoil Starter  
Lubrication Type ......................................................................................................... Splash  
Air Cleaner ....................................................................................................... Dual Element  
Muffler ........................................................................................................... Low Tone Type  
Alternator ................................................................................................... 12v 10 A (68 DL)  
Net Weight (Engine)..................................................................................... 47 lbs (21.4 kg)  
SOUND & VIBRATION LEVELS  
Average Measured Sound Power .............................................................................. 99 dBA  
Guaranteed Sound Power ....................................................................................... 105 dBA  
Average Measured Sound Pressure, at operator position......................................... 87 dBA  
2
Hand-Arm Vibration level ............................................................................ 3.79 m/sec rms  
2
Whole Body Vibration level ......................................................................... 0.86 m/sec rms  
52  
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®
NATIONAL 68 SR & DL TRIPLEX  
PARTS ORDERING INFORMATION  
When ordering replacement parts, always furnish:  
1. Your complete name, address, and phone number.  
2. Model Number and Serial Number (stamped on the main frame rear axle gusset below seat)  
3. Part Number (it is recommended that the correct number be verified with a current Master Price List).  
4. The full Description of the part.  
5. Quantity desired (quantity shown is the total number of parts contained in the particular view shown).  
If the Part Number and the Description of your order do not agree, the Part Number will be used to fill your order.  
Note: For your records and future ordering, fill in the following information:  
Date Purchased  
Model Number  
Serial Number  
Distributor Name  
Address  
Phone  
FAX  
Web Site  
Sales Person  
V-BELT CROSS-REFERENCE CHART  
Function  
National Number  
03901  
Belt Mfr Number  
A29  
Lower Countershaft  
Main Belt  
03902  
B66  
Main Clutch  
03903  
Gates 6844  
A42  
Rear Cutting Unit  
Transport (68DL)  
03905  
03926  
Gates 6841  
Wing Cutting Units (2)  
03931  
A34  
53  
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®
NATIONAL 68 SR & DL TRIPLEX  
55  
68OM-06/03  
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