New Force Motor NF150 Operating instructions

NF150- 150cc Utility Repair Manual
CONTENTS
1.INFORMTION 2
2.MAINTENANCE 6
3. ENGINE REMOVAL AND INSTALLATION 12
4.ENGINEFUELSYSTEM 13
5. ENGINE LUBRICATION AND COOLING SYSTEM 15
6. ENGINE COMBUSTION SYSTEM 16
7.TRANSMISSIONSYSTEM 25
8. FRONT WHEEL AND STEERING SYSTEM 30
9.REARWHEELSYSTEM 38
10. BODY COVER AND EXHAUST PIPE 41
11. ELECTRICAL SYSTEM 43
12. TROUBLE SHOOTING 47

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1. INFORMATION
1.1SAFETY
＊Gasoline is extremely flammable and is explosive under certain condition.
Do not smoke or allow spark or flames in your work area.
＊Never run the engine in a closed area. The exhaust contains poisonous carbon
monoxide gas that may cause loss of consciousness and lead to death.
＊The battery electrolyte contains sulfuric acid. Protect your eyes, skin and clothing.
If you contact it , flush thoroughly with water and call a doctor if electrolyte gets
In your eyes.
1.2NOTES
All information, illustrations, directions and specifications included in this publication
are base on the latest product information available at the time of approval for printing.
NEW FORCE MOTOR CO., LTD. reserves the right to make changes at any time without
notice and without incurring any obligation whatever.
No part of this publication may be reproduced without written permission.

3
1.3 SPECIFICATION
ENGINE
Type Air-Cooling4-Stroke
Displacement 149.5cc
BoreandStroke 57 x 57.8mm
Compression 9.2:1
Maximum Torque 1.2kgm@6000rpm
Carburetor Kei-hin009Qga
Ignition CapacitorDischarge
Starting Electric&KickStarter
Lubrication Oil Pump Supply
Transmission Automatic(C.V.TV-belt)andReverse
CHASSIS
Overall Length 1720mm
OverallWidth 920mm
Overall Height 1030mm
SeatHeight 790mm
Wheelbase 1130mm
Ground Clearance 220mm
Dry Weight 182kg
FuelTankCapacity 11liter
SUSPENSION
Front Double A arm
Rear Swingarm
BRAKES
Front Drum x 2 (EEC SPEC. ADDITION)
Rear Diskx1(FOOTBRAKESYSTEM)
TIRIES
Front USA {22”×7”－10” EEC{21”×7”－10”
Rear SPEC. {22”×10”－10” EEC{21”×10”－8”
ARTILLERY GREEN/VIPER RED/LIGHT YELLOW
COLORING
Specifications subject to change without notice.

4
1.4 SERIAL NUMBER
The frame serial number is stamped on the front of the frame.
The engine serial number is stamped on the left side of the crankcase.

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1.5 TORQUE VALUES
ENGINE
＊Cy1inder head hut…………………………………………………………………2.0kgm
＊Spark plug…………………………………………………………………………1.2kgm
＊Stud bolt……………………………………………………………………………0.9kgm
＊Alternator wheel nut…………………………………………………………… …5.5kgm
FRAME
＊Handlebar upper holder bolt………………………………………………………2.7kmg
＊Steering stem nut…………………………………………………………………..11.0kgm
＊Steering stem shaft holder bolt…………………………………………………….2.0kgm
＊Front and rear cushion bolt………………………………………………………...4.0kgm
＊Steering stem rod nut………………………………………………………………4.0kgm
＊Aarm bolt………………………………………………………………………….4.0kgm
＊A arm holder bolt…………………………………………………………………..6.0kgm
＊Front wheel nut………………………………………………………………….....4.5kgm
＊Disk holder bolt……………………………………………………………………5.5kgm
＊Driven sprocket holder bolt………………………………………………………..4.0kgm
＊Drive chain sprocket nut…………………………………………………………..11.0kgm
＊Rear axle and tire castle nut……………………………………………………….11.0kgm
＊Rear wheel bolt…………………………………………………………………….4.5kgm
＊Exhaust muffler mounting bolt…………………………………………………….1.2kgm
＊Engine fr hanger bolt………………………………………………………………5.0kgm
＊Engine rr hanger bolt………………………………………………………………5.0kgm
＊R/L knuckle and tire castle nut…………………………………………………….11.0kgm
＊Swing arm axle nut……………………………………………………………… ..11.0kgm
＊RR axle holder bolt………………………………………………………………...6.0kgm
＊RR axle holder nut…………………………………………………………………25.0kgm
＊RR brake caliper fix bolt…………………………………………………………...3.2kgm

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2. MAINTENANCE
2.1 MAINTENANCE DATA 2.8 IDLE SPEED
2.2 MAINTENANCE SCHEDULE 2.9 DRIVE CHAIN
2.3 FUELTUBE 2.10 BRAKE SYSTEM
2.4 THROTTLE OPERATION 2.11 WHEELS AND TIRES
2.5 THROTTLE CABLEADJUSTMENT 2.12 STEERING SYSTEM
2.6 AIR CLEANER 2.13 TOE-IN
2.7 SPARK PLUG 2.14 GEAR OIL
2.1 MAINTENANCE DATA
SPECIFICATION
SPARK PLUG:
SPARK PLUG GAP: 0.6-0.7 mm
RECOMMENDED SPARK PLUGS: NGK CR7 HSA
THROTTLELEVERFREEPLAY: 5-10mm
IDLE RPM 1550 ± 50 rpm
BRAKELEVERFREEPLAY: 15-25mm
DRIVECHAINSLACK 25-40mm
FRONT-REAR TIRE PRESSURE 3.2psi (22kpa)
TOE-IN 5±10mm
TORQUE VALUES
SPARK PLUG 1 .2kgrn
STEERING STEM ROD NUT 4.Okgm
ENGINEOIL JASOFCGradeorsamedegree
oil
GEAR LUBRICATION OIL SAE 30 900cc
MISSIONOIL SAE9O200cc
2.2 MAINTENANCE SCHEDULE
The maintenance intervals in the follow table is based upon average riding, conditions.
Riding in unusually dusty areas, require more frequent servicing
INITIAL SERVICE
(First week)
REGULAR SERVICE
(Every 30 operation days)
EVERY YEAR
FUEL LINE
HROTTLE OPERATION
AIR CLEANER
SPARK PLUG
CARBURETOR IDLE
RPM
DRIVE CHAIN
BRAKE SHOE WEAR
BRAKE SYSTEM
NUT, BOLT, FASTENER
WHEEL
STEERING SYSTEM
SUSPENSION SYSTEM
GEAROIL(30#)
MISSION OIL (90#)
I
I
I,L
I
I
I
I
C
I
I
I,L
I
I
I
R
I
I
I
I
R
Note-I：Inspect and Clean，Adjust，Lubricate or Replace，if necessary
C：Clean L：Lubricate R：Replace
2.3 FUELTUBE
Inspect the fuel lines for deterioration, damage or

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leakage and replace if necessary.
2.4 THROTTLE OPERATION
inspect for smooth throttle lever full opening and
automatic full closing in all steering positions.
Inspect if there is no deterioration or damage in the
throttle cable, replace it if necessary.
Check the throttle lever, free play is 5-10 mm at the
tip of the throttle lever.
Disconnect the throttle cable at the upper end.
Lubricate the cable with commercially lubricant to
prevent premature wear.
2.5 THROTTLE CABLE ADJUSTMENT
Slide the rubber cap of the adjuster off the throttle.
Housing, loosen the lock nut and adjust the free play
of the throttle lever turning the adjuster on the
throttle housing.
Inspect the free play of the throttle lever.
2.6 AIR CLEANER
Unscrew the air cleaner cover screws.
Pull out the air filter element from the air cleaner case.
Wash the element in non-flammable solvent, squeeze
out the solvent thoroughly.
Let it dry.
Soak the filter element in gear oil and then squeeze
out the excess oil.
Install the element into air cleaner carefully.

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2. 7 SPARK PLUG
This spark plug located at the front of the engine .
Disconnect the spark plug cap and unscrew the spark plug .
Check the spark plug electrodes for wearing .
Change a new spark plug if the electrodes and insulator tip
appear unusually fouled or burned .
Discard the spark plug if there is apparent wear or if the
insulator is cracked or chipped .
The spark plug gap shall keep in 0 . 6 一0 . 7mm .
With the sealing washer attached , thread the spark plug in
by hand to prevent crossing thread .
Tighten the spark plug with 1 . 2kgm
2. 8 IDLE RPM
Connect a engine speed meter .
Warm up the engine , 10 minutes are enough .
Turn the idle - speed adjust screw on the carburetor to
obtain the idle speed . " Turn in " ( clockwise ) will get
higher speed . " Turn out " ( counter clockwise ) will get
lower speed .
IDLE RPM 1550 士50rpm
2. 9 DRIVE CHAIN
When the drive chain becomes very dirty , it should be
removed , cleaned and lubricated by specify lubricator .
Using commercial chain lubricant to lubricate the drive
chain ,
Clean the drive chain with kerosene and wipe it dry .
Inspect the drive chain for possible wear or damage .
Replace the chain , if it is worn excessively or damaged
Inspect the sprocket teeth , if it is excessive wear or
damage , replace it .

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Adjust the chain slack.
Loose the lock bolts (4pcs) then adjust the drive chain
slack by turn the adjusting nut.
Tighten the four lock bolts.
2.10 BRAKE SYSTEM
Inspect the front brake lever and cable for excessive play
or other damage.
Replace or repair if necessary.
Measure the free play of the brake lever at the end of the
brake lever. The standard of free play is 15-25mm.
Inspect the rear brake lever and cable for excessive play
or other damage.
Replace or repair if necessary.
Measure the free play of the rear brake lever at the end of
the lever. The standard is 15-25mm.

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2.11 WHEELS AND TIRES
Inspect the tire surfaces for cuts, nails or other sharp
objects.
Check the tire surfaces at cold tire condition.
The standard of tire pressure is 3.2psi (22kpa).
2.12 STEERING SYSTEM
Check the free play of the handle steering
front wheels, turn straight ahead.
When there is excessive play, inspect the steering
stern rod.
2.13 TOE-IN
Let the vehicle on level ground and the front wheels
facing straight ahead.
Mark the centers of the tires to indicate the axle center
height.
Measure the distance between the marks.
(750±10mm)
Carefully move the vehicle back, let the wheels have
turned 1800 , so the marks on the tires are aligned
with the axle center height.
Measure the distance between the marks.
Calculate the difference in the front and rear
measurements.
Toe-in: 5±10mm

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If the toe-in is out of standard, adjust it by changing
the length of the steering stem rod equally by turning
the steering stem rod.
Tighten the lock nuts.
torque: 4.Okgrn
2.14 GEAR OIL
Gear oil needs to be changed every 30 operating day.
There is a gear oil release bolt at the rear of engine.
Unscrew this release bolt and can let the dirty oil
flow out. (STEP 1)
The re-add oil hole is on the engine case beside crank
case and tinder crank case. (STEP 2)
Re-install the oil filler cap. (STEP 3)

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3. ENGINE REMOVALAND INSTALLATION
3.1 ENGINE SHALL BE REMOVED IN THE CONDITIONS OF NECESSARY
REPAIRMENT OR ADJUSTMENT TO THE TRANSMISSION AND
COMBUSTION SYSTEM ONLY
3.2 ENGINE REMOVAL
Remove the seat and rear body cover (Chapter 10)
Remove the spark plug cap from the spark plug.
Remove the exhaust pipe.
Disconnect the carburetor cable by unscrew wire on
the carburetor.
Disconnect the wire connectors. There are three
connectors for carburetor auto-choke, starter motor
and generator respectively.
Remove the drive chain retaining clip and master link,
and remove the drive chain.
Remove the engine hanger bolt on the engine.
3.3 ENGINE INSTALLATION
Engine installation is essentially the reverse order of
removal.
The torque lie of engine hanger bolt is 5.Okgrn.
Route the wires and cable in reverse order properly.

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4.1 TROUBLESHOOTING
ENGINE CAN NOT START------------------------------* NO FUEL IN TANK
* NO FUEL TO CARBURETOR
*TOO MUCH FUEL GO INTO CYLINDE
HEAD
* NO SPARK AT PLUG
* AIR CLEANER CLOGGED
ENGINE IDLES UNSTEADY, -------------------------* UNPROPER ADJUSTMENT TO THE
IDLE RPM SCREW
* IGNITION MALFUNCTION
* FUEL/AIR MIXTURE RATIO NO GOOD
* AIR CLEANER DIRTY
* INSULATOR LEAKS BROKE
* FUELTANK CAP BREATHING HOLE
CLOGGED
* AUTO CHOKE ELECERICS, SHORT
CIRCUIT
LEAN MIXTURE--------------------------------------* FUELJET OF CARBURETOR CLOGGED
* FUEL TANK CAP BREATHING HOLE
CLOGG ED
* FUEL FILTER CLOGGED
* FUEL FLOWS IN THE TUBE
UNSMOOTHLY
* FLOAT LEVEL IN CARBURETOR TOO
LOW
RICH MIXTURE--------------------------------------* FLOAT NEEDLE VALVE IN
CARBURETOR FAULTY
* FLOAT LEVEL TOO HIGH
* AIR DUCT IN CARBURETOR IS
CLOGGED
* AIR CLEANER DIRTY

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4.2 CARBURETOR
RE MOVAL
RE MOVALTHE AIR CLEANER.
DISCONNECT AUTO CHOKE ELECTRIC WIRE.
REMOVE THE FUELTUBE AND THE NEGATIVE
FUEL TUBE.
LOOSEN THE SCREW SO THAT TO LET OUT
THE FUEL.
LOOSEN THE THROTTLE WIRE ADJ USTING NUT
AND THE FIXED NUT.
THEN, REMOVE THE THROTTLE WIRE.
LOOSEN THE INLET PIPE BAND AND A/C ASSY
TUBE BAND.
REMOVE THE CARBURETOR.
AUTO CHOKE
OPERATIONAL INSPECTION CHECK THETWO
RESISTANTS OF AUTO CHOKE.
STANDARD: BELOW 5Ω(ENGINE STOPPED FOR 10
MINUTES AND ABOVE)
ASSEMBLY
INSTALL THE CARB. BY MATCHING ITS RAISED
PART WITH THE INLET PIPE CAP.
TIGHTEN BOTH THE BANDS OF INLET PIPE AND
A/C AS’SY TUBE.
INSTALL THE THROTTLE WIRE ON THE ROLLER.
INSTALL THE NEGATIVE FUEL TUBE AND THE
FUEL TUBE.
CONNECT AUTO CHOKE WIRE MUST MAKE SURE
THE FOLLOWING ADJUSTMENT THE THROTTLE
WIRE AND IDLE RPM AFTER INSTALLATION.

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5. ENGINE LUBRICATIONAND COOLING SYSTEM
5.1 ENGINE LUBRICATION SYSTEM
The pump gears of oil pump is driven by the engine crankshaft. Pump gears rotate the drive shaft in
oil pump. This shaft sent the lubricating oil into the crankcase and the crank shaft cam shaft.
The oil drops and foam cover the cylinder inner wall, piston surface and piston rings.
5.2 CAUTION
Having enough oil supply to engine is very important.
If the oil quantity is not enough, this engine will be serious scratched, and then this engine will stop,
even cannot work again.
When this engine is serious scratched, you need to change the piston, piston rings and cylinder
together.
Also you need to check the combustion system and lubrication system carefully.
5.3 OIL PUMP
The quantity of oil that delivers out from oil pump which will be increased by the engine speed.
5.4 COOLING SYSTEM
The air is sucked by the engine cooling fan.
The cooling fan is on the right side of engine.
The air is forced to flow through cylinder rim and cylinder head. So, the cylinder and piston will not
over heat.
5.5 TROUBLESHOOTING
NO ENOUGH OIL SUPPLY TO ENGINE－－－* THE OIL LEVEL IN OIL TANK IS TOOLOW.
* OILTUBES WERE NOT FIXED WELL.
* OIL HAS LEAKAGED FROM TUBE ENDS.
* OIL TUBES WERE BROKEN.
* OILTUBES WERE CLOGGED.

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6. ENGINE COMBUSTION SYSTEM
6.1 TROUBLESHOOTING
LOW COMPRESSION－－－－－－－* CYLINDER HEAD
HEAD GASKET LEAKING OR DAMAGED
WARPED OR CRACKED CYLINDER HEAD
* CYLINDER OR PISTON RINGS WORN OUT
HIGH COMPRESSION－－－－－－ * EXCESSSIVE CARBON BUILD-UPON PISTON
HEAD OR IN COMBUSTION CHAMBER
EXCESSIVE NOISE－－－－－－－ * PISTON AND CYLINDER WORN OUT
* EXCESSIVE CARBON BUILD-UP
EXCESS SMOKE－－－－－－－－ * CYLINDER OR PISTON RINGS WORN OUT
* IMPROPER INSTALLATION OF PISTON RINGS
* PISTON OR CYLINDER WALL SCORED OR
SCRATCHED
OVERHEATING－－－－－－－－－* EXCESSIVE CARBON BUILD-UPON THE PISTON
OR COMBUSTION CHAMBER
* ENGINE COOLING SYSTEM (FAN, CYLINDER
COVER....) WORKS BADLY.
* OIL SUPPLY IS OUT OF ORDER.
* WRONG IGNITION TIMING

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6.2 CYLN HEAD / VALVE
REMOVE CAM SHAFT
UNSCREW THE FOUR BOLTS WHICH FIX THE
HEAD COVER.
REMOVE HEAD COVER.
UNSCREW CAM CHAIN TENSIONER SCREW,
AND TAKE OFF O-RING.
TIGHTEN THE CAM CHAIN TENSIONER SCREW
IN A CLOCKWISE DIRECTION.
UNSCREW THE TWO BOLTS WHICH FIX THE
CYLN HEAD.
REMOVE CAM SHAFT HOLDER, NUT, WASHER.
THEN THE CAM SHAFT CAN BE REMOVE.
MEASURE CAM SHAFT HIGH ANGLE.
SERVICE LIMIT: IN 26.23mm
EX 26.12mm

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INSPECT THE CAM SHAFT BRG, IF IT IS WEAROR
DAMAGE REPLACE IT
REMOVE CAM SHAFT HOLDER
USEA 5mm BOLT TO TAKE OUT THE ROCKER ARM
SHAFT, STOPER PLATE AND ROCKER ARM.
MEASURE THE ACTION OUTER DIAMETERS OF
ROCKER ARM SHAFT AND HOLDER.
SERVICE LIMIT: 10.10mm ABOVE (HOLDER)
MEASURE THE ACTION OUTER DIAMETERS OF
ROCKER ARM SHAFT AND ROCKER ARM.
SERVICE LIMIT: 9.9/mm ↓(SHAFT)
10.10mm↑(ROCKER ARM)
REMOVE CYLN HEAD
REMOVE SHROUD A/B, INLET
PIPE AND HEAD COVER.
REMOVE CAM HOLDER AND
MUFFLER.

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REMOVE CYLN HEAD
TAKE OFFTHE DOWEL PIN AND GASKET.
REMOVE CAM CHAIN GUIDE.
ATTENTION: -- DO NOT HARM THE CYLN
INSTALLATION SURFACE.
-- PRE VENT ANYTHING FROM
DROPPING INTO THE CRANK CASE.
DISASSEMBLY CYLN HEAD
REMOVE RETAINER, VALVE SPG, SPG SEAT,
VALVE STEM SEAL.
CLEAR THE COM BUST1ON CARBON.
ATTENTION: DO NOT HARM THE CYLN HEAD
INSTALLATION SURFACE.
MEASURE THE INNER/OUTER VALVE SPG
FREE LENGTH.
SERVICE LIMIT: INNER 31.2 mm MIN
OUTER34.1 mm M1N
CHECK IF:
VALVE GUIDE BENT, BURNED.
VALVEAND GUIDE OPERATE SMOOTHLY.
VALVE OUTER DIAMETER
MEASURETHE VALVE OUTER DIAMETER
SERVICE LIMIT: 4.9mm MIN

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6.3 INTALLTHE CYLN HEAD
DOWEL PIN AND GASKET INSTALL ON THE
CYLINDER.
INSTALL THE CAM CHAIN TENSIONER.
INSTALL THE CYLN HEAD.
INSTALL THE CAM HOLDER
ASSEMBLY THE CAM HOLDER.
MATCH THE “EX ” MARK ON CAM HOLDER
WITH THE EX VALVE.
TURN THE “T ” MARK OF FLY WHEEL TO
MATCH WITH R COVER INDICATOR POINT.
PLACE THE CAM SPKT HOLE FACES.
ABOVE OF CYLN HEADTHE TWO DENTED
PUCH POINTS ARE PARALLEL WITH THE CYLN
HEAD INSTALLATION SURFACE.
INSTALL THE CAM SHAFT ON THE CYLN HEAD
INSTALL THE CAM CHAIN ON THE SPKT.