Eton VECTOR ST 250 User manual

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CONTENTS
GENERAL INFORMATION
1.Information…………………………………………………….…2
2.Maintenance………………………………………………….…..6
3.Engine Removal & Installation…………………………..…..14
ENGINE
4. Lubrication System……………………………………………16
5. Fuel System…………………………………………………….23
6. Cylinder HEAD & Cylinder Valve……………………….…..34
7. Cylinder & Piston…………………….………………………..50
8.V-Belt driving system…………………………………………58
9. Transmission…………………………………………………...72
10. ACG & Start one way clutch………………………………..84
11. Crankcase & Crank…………………………………………..93
12. Cooling System……………………………………………..101
CHASSIS
13.Steering & Suspension…………………………................113
14. Front Wheel & Brake System…………………………….121
15. Rear Wheel & Brake System………………………….….127
16. Fenders & Exhaust Pipe……………………………….....136
17. Electrical System…………………………………………..142
18. Trouble Shooting…………………………………………..151

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1. INFORMATION
1.1 SAFTY
1.2 NOTES
1.3 SPECIFICATION
1.4 SERIAL NUMBER
1.5 TORQUE VALUE
1.1 SAFETY
GASOLINE
Gasoline is extremely flammable and is explosive under certain condition.
Do not smoke or allow sparks or flames in your work area.
●CARBON MONOXIDE
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.
●BATTERY ELECTROLYTE
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.
● HOT PARTS
Engine and exhaust pipe become very hot and remain hot for one hour after the
engine is run. Wear insulated gloves before handling these parts.
● USED ENGINE/GEAR OIL
Used engine oil and gear oil may cause skin disease if repeatedly contact with
the skin for long periods.
Keep out of reach of children.
1.2 NOTES
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.
JI-EE Dynamic Technology Industry 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.
1.3 SPECIFICATION ENGINE
Type 4 Stroke，Single Cylinder, Water cooled
Displacement 249c.c.
Bore and Stroke 71 mm x 63 mm

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Compression 10.6:1
Maximum Hp 19ps / 5600
Maximum Torque (Nm/rpm) 22.3 Nm / 5500
Carburetor
Ignition DC-CDI
Starting Electric
Lubrication Auto oil injection
Transmission Automatic (C.V.T. V-belt + Reverse)
CHASSIS
Overall Length 1815mm
Overall Width 1062mm
Overall Height 1130mm
Wheel base 1193mm
Ground Clearance 150mm
Dry Weight 225kg
Fuel Tank Capacity 12L
SUSPENSION
Front Double A-Arm & Adjustable
Shocks
Rear Swing Arm & Adjustable Shock
BRAKES
Front Hydraulic Disc*2
Rear Hydraulic Disc*1
TIRES
Front 21x7-10
Rear 22x10-10
PRESSURE 【psi ( kgf/cm2)】
Front 12(0.8)
Rear 12(0.8)
COLORING
Specifications subject to change without notice.

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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.
Side Frame serial number Engine serial number
Frame serial number

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1.5 TORQUE VALUES
STANDARD
●5 mm bolt and nut 5 N.m (3.5 lbf.ft)
●6 mm bolt and nut 10 N.m (7.2 lbf.ft)
●8 mm bolt and nut 22 N.m (16 lbf.ft)
●10 mm bolt and nut 35 N.m (25 lbf.ft)
●12 mm bolt and nut 55 N.m (40 lbf.ft)
ENGINE
●Cylinder head nut 28 N.m (20.7 lbf.ft)
●Spark plug 12 N.m (8.9 lbf.ft)
●Cylinder head bolt 20 N.m (14.8 lbf.ft)
●Alternator bolt 8 N.m (5.9 lbf.ft)
FRAME
●Handlebar upper holder bolt 24 N.m (17.7 lbf.ft)
●Throttle housing cover screw 4 N.m (2.9 lbf.ft)
●Steering shaft nut 50 N.m (36.9 lbf.ft)
●Steering shaft holder bolt 33 N.m (24 lbf.ft)
●Wheel rim bolt 18 N.m (13.3 lbf.ft)
●Tie rod lock nut 35 N.m (25.8 lbf.ft)
●King pin nut 40 N.m (29 lbf.ft)
●Handlebar lower holder nut 40 N.m (29.5 lbf.ft)
●Front wheel bolt 24 N.m (17.7 lbf.ft)
●Front axle castle nut 40-60 N.m (30-45 lbf.ft)
●Front brake arm nut 4 N.m (3.0 lbf.ft)
●Rear brake arm nut 7 N.m (5.2 lbf.ft)
●Rear axle castle nut 40-60 N.m (30-45 lbf.ft)
●Rear wheel bolt 24 N.m (17.7 lbf.ft)
●Exhaust muffler mounting bolt 30 N.m (22.1 lbf.ft)
●Engine hanger bolt 30 N.m ( 22 lbf.ft)
●Rear axle holder bolt 90 N.m (65 lbf.ft)
●Swing arm pivot nut 90 N.m (65 lbf.ft)
●Rear shock absorber mounting nut 45 N.m (33 lbf.ft)

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2. MAINTENANCE
2.1 MAINTENANCE DATA 2.8 IDLE SPEED
2.2 MAINTENANCE SCHEDULE 2.9 DRIVE CHAIN
2.3 FUEL TUBLE 2.10 BRAKE SYSTEM
2.4 THROTTLE OPERATION 2.11 WHEELS AND TIRES
2.5 THROTTLE CABLE AJUSTMENT 2.12 STEERING SYSTEM
2.6 AIR CLEANER 2.13 TOE-IN
2.7 SPARK PLUG
2.1 MAINTENANCE DATA
SPECIFICATION
SPARK PLUG
SPARK PLUG GAP 0.8 mm
RECOMMENDED SPARK PLUGS NGK CR8E
THROTTLE LEVER FREE PLAY 5-10 mm
IDLE SPEED 1700±100 rpm
BRAKE LEVER FREE PLAY 15-25 mm
DRIVE CHAIN SLACK 10-25 mm
TOE-IN 5±10 mm
TORQUE VALUES
SPARK PLUG 12-19 N.m
TIE-ROD LOCK NUT 35-43 N.m
ENGINE OIL 1.4 Liter (1.2Liter for change)
GEAR LUBRICATION OIL 750cc (650cc for change)

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2.2 MAINTENANCE SCHEDULE
The internal maintenance in the following table is based on average riding, normal conditions.
Riding in unusually dusty areas, require more frequent servicing.
300KM Every
1000KM Every 3000KM Every 6000 KM Every 12000KM Notes
1 Month 3 Months 6 Months 1 Year 2 Years
Fuel Lines I I R
Throttle Operation I I
Air Filter I C R
Fuel Filter R
Spark Plug I I R
Drive Chain I, L Lubricate for every 1 month
Brake Shoes I
Brake System I I
Brake Fluid I R
Nuts, Bolts & Fasteners I
WHEEL/TIRES I I
Wheels I I
Steering System I I
Suspension System I I
C.V.T Drive belt I R
Transmission Oil R Replace for every 3,000km or 6 Months
Engine Oil R Replace for every 3,000km or 6 Months
Battery I I,C I,C
Oil Filter (Screen) C C
Valve Clearance I I
Coolant I I R
Cooling Fan I I
Carburetor (Idle Speed) I I
Choke I
Note – I: Inspect and Clean, Adjust, Lubricate or Replace, if necessary
C: Clean L: Lubricate R: Replace
2.3 FUEL TUBE
Inspect the fuel lines for deterioration, damaging or
leakage and replace if necessary.

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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, damage or kink 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 by turning the adjuster on
the throttle housing. Inspect the free play of the
throttle lever.
2.6 AIR CLEANER
Please remove the four hooks, and then disassemble
two screws inside the air cleaner case.
Pull out the air filter element from the air cleaner case.
Washing 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 every component into air cleaner in the reverse
order of removal.
Note: for more detail please check chapter 5-10
Throttle

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2.7 SPARK PLUG
This spark plug is located at the front of the engine.
Disconnect the spark plug cap and unscrew
the spark plug.
Check the condition of spark plug electrodes wear.
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 0.6-0.7mm
With the sealing washer attached, thread the
spark plug in by hand to prevent crosses threading.
Tighten the spark plug with 12-19 N.m
2.8 IDLE SPEED
Connect an 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 SPEED: 1700±100 rpm
2.9 DRIVE CHAIN
Stopping the ATV and shift the transmission into neutral(N) .
Measure the drive chain slack midway between the
sprockets.
Chain slack =15~25mm (5/8~1 inch)
Adjust the chain slack.
Loosen the lock nuts and turn drive chain adjusting nuts
until get the correct slack.
Tighten the axle holder bolts.
Torque = 90N.m (65 lbf.ft)

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When the drive chain becomes very dirty, it should be
removed, cleaned and lubricated by specify lubricator.
Please use special chain oil to lubricate the drive
chain.
Clean the drive chain with kerosene and wipe it dry.
Inspect the drive chain for any possible wearing or damaging.
Replace the chain, if it is worn excessively or damaged.
Inspect the sprocket teeth, if it is excessive wearing
or damaging, please replace it.
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 15-25 mm.
The parking brake is shown on the picture. The position
of parking Off is on the left side. Turn parking brake to
right side is parking on
Parking Off
Parking Brake
Parking On
Brake level
Adjustable nut

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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 15-25 mm.
NOTE:
The second method to adjust brake level is under the
driver seat and rear brake component.
Because the brake system is different, ones need to adjust it
to reach a proper brake level.
2.11 WHEELS AND TIRES
Inspect the tire surfaces for cuts, nails or other
sharp objects.
Check the each tire surface at cold tire condition.
*The standard of tire pressure is 12(0.8) psi ( kgf/cm2)
Brake level Adjustment
Adjustable nut
Parking Brake Adjustable nut
Rear Brake
Front Brake

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2.12 STEERING SYSTEM
Check the free play of the steering shaft with the front
wheels, turned straight ahead.
When there is excessive play, inspect the tie-rod,
kingpin bushing and ball joint.
STEERING SHAFT HOLDER BUSHING
Remove the front fender first.
Remove the steering shaft holder and check the
steering shaft bushing for wears or damage.
If the bushing is worn or damaged, please change a new
one.
Grease the steering shaft bushing and install the parts
in the reverse order of removal.
Torque: steering shaft holder bolt: 33 N.m (24 lbf.ft)
2.13 TOE-IN
Keep 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.

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Carefully to move the vehicle back, let the wheels
turn 180 degree, 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
If the toe-in is out of standard, adjust it by changing
the length of the tie-rods equally by turning the tie-rod
while holding the ball joint.
Tighten the lock nuts.
Torque: 35-43 N.m
Lock Nuts

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3. ENGINE REMOVE AND INSTALLATION
3.1 REPAIR CONDITION 3.3 ENGINE INSTALLATION
3.2 ENGINE REMOVAL
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
Before removing engine, you need to remove all of components such as seat, front and back fender,
fuel tube, exhaust pipe, carburetor cable and drive chain…etc. You can then see three hanger bolts which have
screwed on engine.
Loosen these three hanger bolts. You have succeeded to remove this engine.
There are some pictures to describe main step of removing engine.
Disconnect the wire connectors. There are three
connectors for carburetor auto-choke, starter motor
and generator respectively.
Remove the drive chain cover.
Remove the drive chain retaining clip and master link,
and remove the drive chain.
Hanger bolt

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3.3 ENGINE INSTALLATION
The Engine installation is essentially in the reverse order of removal.
The torque of engine hanger bolt is 30 N.m
Route the wires and cable in reverse order properly.
Hanger bolt

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4. LUBRICATION SYSTEM
4-1 Mechanism Diagram
4-2 Precautions in Operation
4-3 Troubleshooting
4-4 Engine Oil
4-5 Engine Oil Strainer Clean
4-6 Oil Pump
4-7 Gear Oil
4-1 Mechanism Diagram
Valve Rocker Arm
Cam Shaft
Spray Lubrication
Spray Lubrication
Press-In Lubrication
Press-In Lubrication
Oil Route
Con-Rod Oil Route
Oil Pump
Rotate Direction
Oil Strainer

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4-2 Precautions in Operation
General Information:
zThis chapter contains maintenance operation
for the engine oil pump and gear oil
replacement.
Specifications
Engine oil quantity Disassembly: 1400 c.c.
Change: 1200c.c.
Oil viscosity SAE 10W-30 (Recommended
King serial oils)
Gear oil Disassembly: 750c.c.
Change: 650c.c.
Gear oil viscosity SAE 140
(Recommended SYM Hypoid gear oils)
單位:mm
Items Standard (mm) Limit (mm)
Inner rotor clearance 0.15 0.20
Clearance between outer rotor and body 0.15~0.20 0.25
Oil pump
Clearance between rotor side and body 0.04~0.09 0.12
Torque value
Torque value oil strainer cap 1.5~3.0kgf-m
Engine oil drain bolt 1.9~2.5kgf-m
Gear oil drain bolt 1.0~1.5kgf-m
Gear oil join bolt 1.0~1.5kgf-m
Oil pump connection bolt 0.8~1.2kgf-m
4-3 Troubleshooting
Low engine oil level
yOil leaking
yValve guide or seat worn out
yPiston ring worn out
Low oil pressure
yLow engine oil level
yClogged in oil strainer, circuits or pipes
yOil pump damage
Dirty oil
yNo oil change in periodical
yCylinder head gasket damage
yPiston ring worn out

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4-4 Engine Oil
Turn off engine, and park the ATV in flat surface
with main stand.
Check oil level with oil dipstick.
So not screw the dipstick into engine as
checking.
If oil level is nearly low level, fill out
recommended oil to upper level.
Oil Change
Caution
Drain oil as engine warmed up so that makes
sure oil can be drained smoothly and completely.
Place an oil pan under theATV, and remove oil
drain bolt.
After drained, make sure washer can be re-used.
Install oil drain bolt.
Torque value：1.9~2.5kgf-m
4-5 Engine Oil Strainer Clean
Drain engine oil out.
Remove oil strainer and spring.
Clean oil strainer.
Check if O-ring can be re-used.
Install oil strainer and spring.
Install oil strainer cap.
Torque value：1.5~3.0kgf-m
Add oil to crankcase (oil viscosity SAE 10W-30)
Recommended using King serial oil.
Engine oil capacity: 1200c.c. when replacing
Install dipstick, start the engine for running
several minutes.
Turn off engine, and check oil level again.
Check if engine oil leaks.
Drain bolt
Oil strainer cap
Oil strainer
O-ring

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4-6 Oil Pump
Oil Pump Removal
Remove generator and starting gear. (Refer to
chapter 10) 。
Remove cir clip and take out oil pump driving
chain and sprocket.
Make sure that pump shaft can be rotated freely.
Remove 2 screws on the oil pump, and then
remove oil pump.
Oil Pump Disassembly
Remove the screws on oil pump cover and
remove the cover.
Remove oil pump shaft roller and shaft.
2 screws
Clip
1 screw
Roller

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Oil Pump Inspection
Check the clearance between oil pump body and
outer rotor.
Limit: 0.25 mm
Check clearance between inner and outer rotors.
Limit: 0.20 mm
Check clearance between rotor side face and
pump body
Limit: 0.12 mm
Oil Pump Re-assembly
Install inner and outer rotors into the pump body.
Align the indent on driving shaft with that of inner
rotor.
Install the oil pump shaft and roller.
Install the oil pump cover and fixing pins properly.
Pins