National Mower 68 DL TRIPLEX User manual

MODEL 68 SR TRIPLEX MOWER
MODEL 68 DL TRIPLEX MOWER
NATIONAL MOWER CO. 700 Raymond Ave., P.O. Box 14299
St. Paul, Minnesota 55114-0299, U.S.A.
Phone [phone] – Fax [phone]
www.nationalmower.com
OWNER'S MANUAL
Includes Operation, Maintenance and Parts List
June 2003

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ONE YEAR LIMITED WARRANTY
Fortheperiodofoneyearfromthedateofpurchase(45daysiftheproductisusedforrentalpurposes),
National Mower Company will repair or replace free of charge, for the original purchaser, any part or
parts found by inspection to be defective by our Factory Authorized Service Station or by the Factory
at St. Paul, Minnesota to be defective in material or workmanship or both. All transportation charges
on parts submitted for repair or replacement under this warranty shall be paid for by the purchaser.
This warranty does not include engines, engine parts or tires which are covered under separate
warrantiesfurnishedbytheirmanufacturerorsupplier. Allserviceunderthiswarrantywillbefurnished
and performed by our Factory Authorized Service Stations.
THERE IS NO OTHER WARRANTY EXPRESSED OR IMPLIED
Warranties, including those of merchantability and fitness for a particular purpose, are limited to
one year from purchase or 45 days if the product is rented, and to the extent permitted by law, any
and all implied warranties are excluded. The above remedy of repair and replacement of defective
parts is the purchaser's exclusive remedy for any defect, malfunction, or breach of warranty.
Liability for incidental or consequential damages under any and all warranties is excluded to the
extent permitted by law.
NATIONAL MOWER COMPANY
P.O. Box 14299
700 Raymond Avenue
St. Paul, Minnesota 55114-0299, U.S.A.
Phone [phone]
Fax [phone]
www.nationalmower.com

NATIONAL 68 SR & DL TRIPLEX
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68OM-06/03
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
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.
PleasefurnishuswiththeModelNumber,SerialNumber
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.
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.

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The safety alert words below are used in this manual to
identify potentially hazardous conditions. Their
definitions are:
DANGER means "IMMINENTLY HAZARDOUS
SITUATION! If not avoided, WILL RESULT in death or
serious injury."
WARNING means "POTENTIALLY HAZARDOUS
SITUATION! If not avoided, COULD RESULT in death or
injury."
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.
The safety alert triangle symbols on your mower point
out important safety precautions.
These symbols mean:
ATTENTION!
PERSONAL SAFETY IS INVOLVED!
BECOME ALERT!
OBEY THE MESSAGE!
SAFETY INFORMATION
NATIONAL MOWER SAFE OPERATING
PRACTICES
1. TRAINING
Knowthecontrolfunctionsandhowtostopquickly.READ
THE OWNER’S MANUAL.
2. PREPARATION
Clear the work place of objects which might be picked up
by the blades and thrown.
Handle fuel with CAUTION - it is highly flammable.
• Use an approved fuel container.
• 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.
• Open garage doors to allow ventilation if engine is run
inside – exhaust fumes are dangerous. Do not run en-
gine in any enclosed area.
Keep the mower in safe operating condition. Make sure
that all safety switches are operating properly and all
safety guards are in place at all times, except during
servicing.
Keep all nuts, bolts, and screws tight.
3. OPERATION
Wearapprovedsafety glassesorgoggleswhenoperating
the mower.
Do not allow children to operate mower. Do not allow
adults to operate mower without proper instruction.
Donotcarrypassengers.Keepchildrenandpetsatasafe
distance from an operating mower. Stop the mower if
anyone approaches the mower.
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.
Disengage power to the cutting units and stop the engine
before making any repairs or adjustments.
Disengagepowertothecuttingunitswhentransportingor
not in use.
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.
Watch for dangerous traffic when crossing or near road-
ways.
Neverdirectthedischargeofmaterialfromoperatingreels
toward bystanders nor allow anyone near the mower.
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.
Proceed as follows when mowing:
• Mow only in daylight or in good artificial light.
• Never make a cutting height adjustment while the en-
gine is running.
• Shut the engine off when removing grass or unclogging
reels.
This machine is to be used only as a grass cutter or lawn
mower.
Neveroperate themowerwhile usingdrugs,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.
Donotwearlooseclothing orlooseshoelaces,whichmay
become entangled in mower controls or drive compo-
nents.

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Do not mow in reverse, unless absolutely necessary.
Always look down and behind before and during reverse
motion.
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.)
4. HILL OPERATION
Donotstoporstartsuddenlywhengoinguphillordownhill.
Mowupanddownthefaceofsteepslopes—neveracross
steepslopes.Donotexceedaslopeof15oinanydirection.
Reduce travel speed on slopes and in sharp turns to
prevent tipping or loss of control. Use extreme caution
when changing direction on slopes.
Watch for holes in the terrain and other hidden hazards.
Do not shift into neutral and coast downhill.
Useextremecarewhenmowingneardropoffsorembank-
ments. Themowercouldrolloverifawheelgoes overthe
edge, or if an edge caves in.
Ifmowerstopsgoinguphill,disengagepowertothecutting
units and slowly back down.
5. MAINTENANCE
Never store the mower, with fuel in the tank, inside a
buildingwherefumes couldreachanopenflame orspark.
Allow the engine to cool before storing in any enclosure.
Keeptheenginefreeofgrass,leavesorexcessivegrease
to reduce a fire hazard.
Donot change theenginegovernor settingsoroverspeed
the engine.
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.
ISO SAFE OPERATING PRACTICES
1. TRAINING
Read the instructions carefully. Be familiar with the
controls and the proper use of the equipment.
Never allow children or people unfamiliar with these
instructionstousethelawnmower. Local regulationscan
restrict the age of the operator.
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.
Do not carry passengers.
All drivers should seek and obtain professional and
practicalinstruction. Suchinstruction shouldemphasize:
• 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:
• insufficient wheel grip;
• being driven too fast;
• inadequate braking;
• the type of machine is unsuitable for the task: do not
use mower for unsuitable tasks;
• lack of awareness of the effect of ground conditions,
especally slopes;
• hitching and load distribution: do not hitch or tow
other devices.
2. PREPARATION
Gasoline(petrol)ishighlyflammable.
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.
While mowing, always wear substantial footwear and
long trousers. Do not operate the equipment when
barefoot or wearing open sandals.
Thoroughlyinspecttheareawheretheequipmentistobe
used and remove all objects which can be thrown by the
machine.
Replace faulty silencers.
Beforeusing,alwaysvisuallyinspecttoseethatthereels,
bed knives, and cutting unit assemblies are not worn or
damaged. Replacewornordamagedreelsandbedknives
in sets to preserve balance.
Onmulti-reelmachines,takecareasrotatingonereelcan
cause other reels to rotate.
WARNING

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SAFETY INFORMATION
3. OPERATION
Do not operate the engine in a confined space where
dangerous carbon monoxide fumes can collect.
Mow only in daylight or good artificial light.
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:
• do not stop or start suddenly when going up or downhill;
• engage clutch slowly, always keep machine in gear, es-
pecially when travelling downhill;
• machine speeds should be kept low on slopes and dur-
ing tight turns;
• stay alert for humps and hollows and other hidden haz-
ards;
• never mow across the face of the slope, unless the ma-
chine is designed for this purpose.
Watch out for traffic when crossing or near roadways.
Stopthereel rotation before crossing surfaces other than
grass.
Never direct discharge of material toward bystanders or
allow anyone near the machine while in operation.
Never operate the lawnmower with defective guards, or
without safety devices in place.
Do not change the engine governor setting or overspeed
theengine. Operatingthe engineatexcessivespeedcan
increase the hazard of personal injury.
Before leaving the operator's position,
•disengagethepowertake-offandlowerthecuttingunits;
• shift into neutral and set the parking brake;
• stop the engine and remove the key.
Disengage drive to the cutting units, stop the engine,
remove the ignition key, and disconnect the spark plug
wire:
• before cleaning blockages or unclogging chute;
• 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).
Disengagedriveto attachments when transportingornot
in use.
Stop the engine and disengage drive to attachment:
• before refuelling;
• before removing the grass catcher;
• before making height adjustment;
• before cleaning blockages;
• 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.
Reduce the throttle setting during engine shutdown and
turn the fuel off at the conclusion of mowing.
4. MAINTENANCE AND STORAGE
Keep all nuts, bolts, and screws tight to be sure the
equipment is in safe working condition.
Never store the equipment with fuel in the tank inside a
building where fumes can reach an open flame or spark.
Allow the engine to cool before storing in any enclosure.
To reduce the fire hazard, keep the engine, silencer,
batterycompartment,andfuelstoragearea freeofgrass,
leaves, or excessive grease.
Replace worn or damaged parts for safety.
If the fuel tank has to be drained, this should be done
outdoors.
Whenmachineistobeparked,stored,orleftunattended,
lower the cutting means unless a positive mechanical
lock is used.
Be careful during adjustment of the machine to prevent
entrapment of the fingers between moving blades and
fixed parts of the machine.
Onmulti-reelmachines,takecareasrotatingonereelcan
cause other reels to rotate.
CALIFORNIASAFEOPERATINGPRACTICES
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.

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68OM-06/03
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.
07582 - DIFFERENTIAL SHIFT LEVER
(located on top edge of differential gear drive)
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.
07583 – WING MOWER CLUTCH
(located on top surface of main belt
guard)
Move the clutch lever back to engage
thewingmowerclutch. Movethe lever
forward to put the clutch in neutral.
07584 – TRANSPORT CLUTCH PEDAL
(Model 68 DL)
(locatedontopsurfaceofenginebeltguard)
Pressingthepedalwillcausethemowerto
runinhigh-speedtransportmode. 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.
Before using, disengage the cutting unit
clutches and raise the cutting units to their
transport position.
NEVER USE THE TRANSPORT
CLUTCH WHILE THE CUTTING
UNITS ARE TURNING, OR WHEN THE DIFFEREN-
TIAL SHIFT IS IN REVERSE.
07585 – ENGINE THROTTLE
(located on steering wheel)
Move the engine throttle lever forward
forfastspeed,backwardforslowspeed
07586 – IGNITION KEY (Model 68 DL)
(located on instrument cluster panel)
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,
releasethe key andallowit to rotatetothe
central run position.
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.
07581-MAINENGINECLUTCH
LEVER
(locatedontopsurfaceofengine
belt guard)
Move lever backward to put
clutchinneutralposition,forward
to cause mower to travel
(directiondependsondifferential
shift position).
Engage the clutch slowly. Refer to
instructionsintheOPERATIONSsection
WARNING
WARNING

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07587–IGNITIONKEY (Model68SR)
(located on top surface of main belt
guard)
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.
To stop the engine, turn the key to the
full counterclockwise position.
Refer to the engine manual for details on proper engine
operation.
Disengage cutting unit clutches, engage the parking
brake and remove the key whenever leaving the mower
seat.
07588–PARKINGBRAKELEVER
(locatedontopsurfaceofmainbelt
guard)
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.
07589 – SERVICE BRAKE PEDAL
(located on top surface of main belt
guard)
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.
07599 – WARNING
DECAL
(locatedoninstrument
cluster[68DL]ormain
belt guard [68 SR])
Readandunderstand
the information in the
Owner’s Manual be-
fore operating this
mower.
Readandunderstand
the information in the
Owner’s Manual
before attempting to
repair, service, or
maintain this mower.
Turn off the mower
engine, remove the
ignition key, and
disconnecttheengine
spark plug before
attempting to repair, service, or maintain this mower.
The engine exhaust from this prod-
uct contains chemicals known to
thestateofCaliforniatocausecancer,birthdefects,or
otherreproductiveharm. Donotoperatetheenginein
a confined space where dangerous carbon monoxide
fumes can collect.
Objectsmay be thrownfromthe cut-
ting units. Keep bystanders away
from the mower.
Never allow the mower to freewheel
down hills without the traction drive
engaged. Serious injury or death can result from loss
of control.
Donotoperatethemoweronslopes
greater than 15 degrees.
DANGER
WARNING
WARNING
WARNING
SAFETY AND CONTROL DECALS

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68OM-06/03
07595 – MANUFACTURER & SOUND LEVELS
(located on left side of main belt guard)
Guaranteed sound power level and manufacturer’s
information
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)
07600 – CUTTING UNIT DANGER
(located on top surface of each cutting unit)
Reelsandbedknives on the cutting
units are sharp. Keep hands and
feet away from the cutting units.
Do not attempt to work around the
cuttingunitswhiletheyarerunning.
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.
07083 – SERIAL NUMBER DATA PLATE
(located on mower frame, left side, below seat)
205341 – INSTRUCTIONS for OPTIONAL DIAL-A-
HEIGHT ADJUSTER
(located on the top shield of each cutting unit)
Raise and turn the adjuster knob counterclockwise to
lower the height of cut. Raise and turn the adjuster knob
clockwisetoraisetheheight ofcut. Readtheinstructions
for the Dial-A-Height adjusters in the Operations section
of this manual.
DANGER
DANGER
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.)

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10
205399–OptionalDIAL-A-HEIGHTSCALE(Rearcutting
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.
SAFETY AND CONTROL DECALS

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68OM-06/03
CAUTION
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.
CAUTION
3. Unbolt Seat (3) from crate bracing and lay seat aside
for installation later.
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.
6. Knock down all sides of crate and remove. Roll
mower backwards off of crate base.
UNCRATING INSTRUCTIONS
RECEIPT OF SHIPMENT
Carefullyinspectyourmachineandcratefordamagethat
could have occurred during shipment. If damages or
shortages are noted, have the transportation company’s
representative note this on the bill of lading.
In order to prevent possible damage to the machine or
personal injury, the following uncrating procedure must
be followed:
1. Position Crate (1) on a hard, level surface.
2 Cut and remove all Steel Banding (2). Remove the
entire top of the crate.
CAUTION Wear protective gloves. Steel
banding is sharp. Handle cutting
units carefully. Reels rotate freely
and are very sharp.

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12
ASSEMBLY
WARNING Improper assembly or adjustments
can cause serious injury.
SEAT
1. Mount the Rear Cutting Unit Lifter and Seat Assembly
(A) to the mower frame using (2) 1/2" bolts, nuts, and
washers (B).
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.
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
harnesssocket(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.
REAR CUTTING UNIT
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. 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. Attach the Pull Rod (E) to the cutting unit Pivot Tube
(F) with Pin and Spacers.
NOTE: Before completingassembly, itwillbenecessary
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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68OM-06/03
CAUTION
REAR CUTTING UNIT BELT
InstallRearCuttingUnitBelt(A)fromCountershaftPulley
(B) to outer Drive Pulley (C). Idler Pulley (D) must ride on
topoflowerbelttoprovidepropertension.NOTE:Itwillbe
necessary to raise rear cutting unit to allow enough slack
to get belt over pulleys.
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
releasethe latch, lift the wingcuttingunit handle until
thelatchswings upwardintoanearlyverticalposition.
Carefully lower the cutting unit to the ground. Avoid
droppingthe cuttingunit,as damage mayresult 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
Topreventdamageduringshipment,thereelshavebeen
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.
ENGINE
MOWER IS SHIPPED WITH DRY
ENGINE.DONOTSTARTENGINE
UNTILOILISADDEDTOCRANKCASE. SeeEngine
Manual for additional information.
DIFFERENTIAL
Greasehasbeeninstalledinthedifferentialatthefactory.
For additional information, refer to the Maintenance sec-
tion of this manual.

68OM-06/03
14
PREPARATION
Handle cutting units carefully with
protective gloves. Reels and bed
knives are very sharp. Reels rotate freely and rotating
one reel can cause other reels to rotate.
Movingmachinerycanbedangerous
if not operated properly. Follow all
safeoperatingsuggestionslistedintheSafetyInformation
section of this manual.
Checkthefollowingitemsbeforeeachuseofthemower.
TIRE PRESSURE - Use a tire pressure gage to check
the tire pressure. Fill tires with compressed air as
neededtoobtainthepressurelabelledonthesidewallof
the tire.
ENGINE OIL - Check level on dipstick. Refer to the
engine manual for instructions on adding oil and which
oil viscosity to use.
CAUTION
FUEL - Check fuel level. Add fuel as required. Refer to
the engine manual for type of fuel and other safety
requirements.
ENGINE COOLING - Keep engine cowlings clear of
clippings.
LUBRICATION - Add lubricant to pivots and other
lubrication points as required. Refer to the lubrication
chart in the Maintenance 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.
SAFETY SWITCH OPERATION - Check operation of all
safety switches. Do not use mower if safety switches are
disconnectedornotoperational,asdangerousconditions
will result.
DANGER
OPERATION
The following is a description of the machine controls
and their function.
A. Main Clutch Lever
Engage slowly before full
engagement. Always disengage
the drive when stopping or leaving the machine.
Engages power for
travelandmowing.Down
position is disengaged
and up position is
engaged.
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.
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.
C. Wing Cutting Unit Clutch Lever – Engages drive to
WingCuttingUnits.Pullleverbackanddowntoengage.
Never engage drive unless Wing Cutting Units have
been lowered to cutting position.
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.
WARNING

NATIONAL 68 SR & DL TRIPLEX
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68OM-06/03
D. Transport Clutch (Model 68 DL only)
NEVER USE THE TRANSPORT
CLUTCH WHILE THE CUTTING
UNITS ARE TURNING OR WHEN THE
DIFFERENTIAL SHIFT IS IN REVERSE.
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.
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.
E. Wing Cutting Unit Latch
NEVERATTEMPT TO RAISETHE
WING CUTTING UNITS WHEN
THE WING MOWER CLUTCH IS
ENGAGED.
TheWingCuttingUnitsshouldbelatchedintheirelevated
position whenever the mower is being transported or in
storage.
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).
To release the latch, lift the handle until the latch (E)
swingsupwardintoanearlyverticalposition,thencarefully
lowerthecuttingunitontotheground. Avoiddroppingthe
cutting unit, as damage may result to the cutting unit, the
mower, or your turf.
OPERATION
G. Rear Cutting Unit Clutch
Engages drive to the 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
unlessthe rear cuttingunit
has been lowered to the
cutting position.
H. Rear Cutting Unit Lift Arm
Raisesrearmowertothe
transport position. Pull
handle up, forward and
over center to lock it in
the up position.
J. Seat Position Adjuster Lever
DO NOT OPERATE THE SEAT
SLIDE MECHANISM WHILE THE
MOWER IS MOVING
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.
.
WARNING
WARNING
WARNING

68OM-06/03
16
OPERATION
K. Ignition Switch (Model 68 DL shown)
ALWAYS SHUT OFF THE ENGINE
AND REMOVE THE KEY BEFORE
LEAVING THE MOWER SEAT.
The 68 DL ignition
switch is located on
the instrument
cluster. It is a three-
position switch.
Turn the key
clockwise to the
middle position to
activatetheelectrical
system. Turnthekey
to the full clockwise
position to start the
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.
L. Differential Shift Lever
Never shift while machine is in mo-
tion, as damage to the gears could
result. Always disengage engine clutch before attempt-
ing to shift.
Located on
the mower
differential,
this control
hasthreepo-
sitions: For-
ward, Neu-
tral (center
position),
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.
M. Parking Brake Lever
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.
N. Service
Brake
DepresstheSer-
vice Brake foot
pedaltoslowthe
mower and lock
the rear wheels
in the full stop
position.
Note:Itisbestto
slow the mower
with the throttle and then disengage clutch lever before
applyingbrake.Thispreventsexcessivewearandengine
overload.
SAFETY SWITCHES
YourNational68moweris equipped with safety switches
to monitor the operating conditions of certain machine
functionsandstopthemowerwheneverunsafeconditions
are found.
It is necessary for both the main engine clutch and the
wing cutting unit clutch to be in their neutral position to
starttheengine. The 68 DL alsorequirestheoperator be
intheseat. The68SRdoesnotrequiretheoperatortobe
in the seat to facilitate use of the hand recoil starter.
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.
CAUTION
WARNING

NATIONAL 68 SR & DL TRIPLEX
®
17
68OM-06/03
HEIGHT OF CUT ADJUSTMENT
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.
1. STANDARD ADJUSTERS
Theheight 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.
Itisimportanttogetallrollersadjustedtothesameheight
sothattherewillbeuniformcuttingacrosstheentirewidth
ofthecuttingunit.Donotadjustbysight.Placethemower
on a hard, level surface and place a board or gauge plate
ofthedesiredheightundereachbedknifebackbar.Allow
the rear roller to rest on the level surface. Retighten the
adjusting nuts and remove the gauge plate or board.
STANDARD HEIGHT ADJUSTER
NOTE: Guards removed or cut away to show detail For other machine adjustments, see the Maintenance section of this manual.
DIAL-A-HEIGHT ADJUSTER (OPTIONAL)
2. DIAL-A-HEIGHT ADJUSTERS (OPTIONAL)
Tosettheheightofcut,liftthevinyl capand 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
heightofcutbyapproximately1/32". Afullturn(360°)will
raise or lower the height of cut approximately 1/8".
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 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.
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.
OTHER ADJUSTMENTS
DANGER

68OM-06/03
18
CAUTION
leakage is evident, it is recommended that the grease be
checkedonceeachyear.Checkgreaselevelbyloosening
the bolts in the differential case flanges and spreading
casehalves.Itisnotnecessarytototallydisassemblethe
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).
Donotuseoilin thedifferential case
inplaceofgrease–itwillleakthrough
the seals.
ENGINE
Refer to the engine manual (separately furnished) for
proper lubrication and maintenance instructions.
MAINTENANCE
LUBRICATION
Lubricatethemachineattherecommendedlocationsand
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.
Thelocationandnumberofalllubricatingpointsarelisted
in the chart below. The type and frequency of lubrication
is specified. Use the following photos to locate the
lubrication points on the mower.
DIFFERENTIAL
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
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NATIONAL 68 SR & DL TRIPLEX
®
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68OM-06/03
LUBRICATION POINTS
1. Front wheel bearing
2. Steering Kingpin
3. Front axle pivot
4. Steering column (2 places)
5. Brake pedal pivot
6. Idler pivot bracket (68 DL only)
7. Main clutch handle
8. Wing mower clutch handle
9. Upper countershaft
10. Lower countershaft
11. Wing mower pull rod (2 places)

68OM-06/03
20
MAINTENANCE
LUBRICATION POINTS
12. Rear axle (2 places)
13. Differential input tube
14. Brake drum tube
15. Main axle tube
16. Seat Hinge
17. Rear mower lift arm pivot
18. Rear mower pivot tube
19. Rear mower countershaft (2 places)
20. Rear mower clutch
21. Wing mower lift arm (2 places)