Baja Wilderness (WD400U) OEM Service & Repair Manual
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WD400U Service Manual
For any questions please contact Baja Motorsports at 888-863-2252
Content
Content..................................................................................................................................................2
Chapter I General description...............................................................................................................5
Section Special tools, instruments & meters.................................................................................... 6
(I) Special tools.........................................................................................................................7
Section 2 Identification code, label of model and engine No...............................................................8
Section 3 Points for attention in maintenance......................................................................................8
Section 4 Specification...................................................................................................................... 12
I. How to use conversion table of unit................................................................................... 12
(1) How to use conversion table............................................................................................ 12
(2) Definition of unit...............................................................................................................12
II. Basic specification.............................................................................................................13
III. ATV body ......................................................................................................................... 15
IV. Electric system................................................................................................................. 6
V. Maintenance specification of engine................................................................................. 17
Section 5 Requirements for torque of fastener ................................................................................... 20
(3) General torque specification............................................................................................ 22
Section 6 Lubrication point and type of lubricants............................................................................ 23
(I) ATV body ......................................................................................................................... 23
(II) Engine............................................................................................................................. 24
Chapter II Maintenance and adjustment of vehicle............................................................................ 25
Section 1 Periodic maintenance/lubrication...................................................................................... 25
Section 2 Disassembly and assembly of cushion, fender and fuel tank............................................. 26
(I) Cushion...............................................................................................................................26
(II) Rear fender ...................................................................................................................... 26
(III) Fuel tank.......................................................................................................................... 29
(IV) Front fender ..................................................................................................................... 30
Section 3 Maintenance and adjustment of vehicle body .................................................................... 32
(I) Wear inspection of front and rear brake............................................................................ 32
(II) Adjustment of front brake..................................................................................................32
(III) Adjustment of free clearance of left lever and rear brake pedal.......................................33
(IV) Position adjustment of steering lever ............................................................................. 35
(V) Lubricating oil level inspection of rear driving gearcase................................................. 35
(VI) Replacement of engine oil of rear driving gearcase....................................................... 36
(VII) Rubber sleeve inspection of rear wheel fork................................................................. 37
(VIII) Inspection of steering system....................................................................................... 37
(IX) Adjustment of toe-in of front wheel............................................................................... 38
(X) Inspection of front/rear shock absorber ........................................................................... 39
(XI) Adjustment of rear shock absorber ............................................................................... 39
(XII) Inspection of tire.......................................................................................................... 40
(XIII) Inspection of rim........................................................................................................ 41
Section 4 Maintenance and adjustment of electrical appliance......................................................... 42
(I) Inspection of battery ......................................................................................................... 42
(II) Inspection of fuse............................................................................................................ 43
(III) Replacement of headlight lamp.......................................................................................44
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Section 5 Maintenance and adjustment of engine.............................................................................. 46
(I) Cleaning of air filter ...........................................................................................................46
(II) Inspection of spark plug.................................................................................................. 47
(III) Adjustment of idle speed............................................................................................... 48
(IV) Adjustment of free clearance of throttle grip................................................................ 48
(V) Adjustment of speed limiter ............................................................................................ 49
(VI) Adjustment of valve clearance..................................................................................... 50
(VII) Adjustment of timing chain tension..............................................................................52
(VIII) Measuring of compressive force................................................................................. 53
(IX) Inspection oil quantity of engine................................................................................... 54
(X) Replacement of engine oil and inspection of oil flow ..................................................... 55
Chapter III Repair and maintenance of vehicle body .........................................................................57
Section 1 Rear driving gearcase and driving shaft.............................................................................57
(I) Troubleshooting.................................................................................................................58
(II) Inspection.........................................................................................................................58
(III) Troubleshooting table.....................................................................................................59
(IV) Disassembly .................................................................................................................. 60
(V) Inspection.........................................................................................................................63
Section 2 Rear wheel/Rear brake/Rear wheel axle............................................................................ 64
(I) Removal steps................................................................................................................... 66
(II) Inspection stepes............................................................................................................ .68
(III) Installation steps............................................................................................................. 70
Section 3 Rear shock absorber and rear wheel fork.......................................................................... 74
(I) Disassembling steps......................................................................................................... 75
(II) Checking steps................................................................................................................ 77
(III) Mounting steps.............................................................................................................. 79
Section 4 Steering operation system................................................................................................. 82
(I) Removal steps of steering bar ........................................................................................... 83
(II) Removal steps of steering vertical column welding....................................................... 84
(III) Inspection content......................................................................................................... 85
(IV) Installation steps........................................................................................................... 86
(V) Installation steps of steering bar .................................................................................... 89
Section 5 Front Wheel and Front brake.............................................................................................90
(I) Disassembly ......................................................................................................................92
(II) Installation.......................................................................................................................93
Section 6 Front shock absorber and front wheel fork and Front differential.................................. 95
(I) Disassembly .................................................................................................................... 97
(II) Installment steps.......................................................................................................... 00
Chapter IV Electric appliance........................................................................................................ 02
Section 1 Electric assembly ............................................................................................................ 102
Section 2 Inspect switch................................................................................................................. 04
Section 3 Check headlight lamp..................................................................................................... 105
Section 4 Troubleshooting the ignition system failure................................................................... 106
Section 5 Running starting circuit.................................................................................................. 108
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Section 6 Troubleshooting electric starting system......................................................................... 109
Section 7 Battery will not hold charge............................................................................................. 112
Section 8 Troubleshooting................................................................................................................ 114
Section 9 Inspection of lighting system........................................................................................... 116
(I) Headlight not working..................................................................................................... 116
(II) Taillight not working...................................................................................................... 117
Section 10 Troubleshooting.............................................................................................................. 118
(I) If indicated lamp is out of work....................................................................................... 118
Section 11 Inspection of signal system........................................................................................... 120
(I) If the neutral indicated lamp is out work......................................................................... 120
(II) If the reverse indicated lamp is out work........................................................................ 121
(III) If the HB indicated lamp is out work............................................................................ 122
Chapter V Engine.............................................................................................................................. 123
Section 1 Disassembly of Engine...................................................................................................... 123
(I) Remove the engine from finished ATV .............................................................................. 123
(II) Disassembly of engine..................................................................................................... 145
Section 2 Inspection and maintanence of engine............................................................................... 135
Section 3 Assembly and adjustment of engine................................................................................... 154
(I) Installation......................................................................................................................... 83
Chapter VI Vehicle Troubleshooting.................................................................................................. 180
(I) Starting trouble/difficulty ................................................................................................... 180
4
Chapter I General Description
Section 1 Description
. Front wheel
2. Headlight
3. Forward/Reverse lever
4. Shift pedal
5. Fuel valve
6. Hand-operated lever
7. Air choke
8. Taillight
9. Rear wheel
10. Rear luggage carrier
11. Exhaust silencer
2. Cushion
13. Fuel tank cover
14. Rear brake pedal
15. Front luggage carrier
16. Left rear brake lever
17. Hand-operated parking brake
18. Main switch lock
19. Throttle grip
20. Right front brake lever
21. Left switch unit
22. Left and right mirror (not
shown)
CAUTION:
The ATV you purchased may be slightly different from the pictures in the
manual due to improvements.
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3
4
5
6 7
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0
2 3
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6 7
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20
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5
Section 1 Special tools, instruments and meters
(I) Special tools
There are special tools needed to properly adjust and assemble this unit. These tools are
intended to prevent maintenance defects and damage.
1. Wrench for valve adjustment, mainly used to adjusting the valve clearance. Specification:
3mm, 90890-01311
2. Puller for piston pin, used for removing piston pin.
3. Remover for rotator, mainly for pulling the magneto rotator from crank.
4. Clamp for rotator, for clamping magneto rotator when removing it to prevent it’s rotation due
to torque force.
5. Stop rotating meter for rotator, used for removing and assembling rotator of kick starter.
6. Puller for crank, for disassembling crank from crankcase.
7. Puller for rocker shaft, used for the removing rocker shaft.
8. Compressing tools for spring of valve, for fixing and compressing spring when assembling
valve lock clamp.
9. Assembling and disassembling tools for valve guide.
10. Assembling buffer, used for assembling crank and balancing gear.
11. Hollow sleeve, for assembling crank and balancing gear.
12. Assembling tool for crank, used for assembling crank and balancing gear.
13. Assembling and disassembling joint for universal coupling.
14. Assembling and disassembling disc, used for assembling and disassembling reverse gear.
15. Fixed puller for gear.
6
(II) Instruments and meters
The following instruments and meters can be selected with
reference to the same type of vehicle.
7
Section 2 Identification code, label
of model and engine No.
Identification code
Engraved in the left or right side of the front
supporting main tube of engine of frame
Engine No.
This is engraved on the top middle part of the
right crankcase of engine.
Section 3 Points for attention in maintenance
1. Preparation when disassembling
• Clean and dirt or mud from vehicle.
• Be sure to use proper tools when disassembling
• Keep all the components away from fire. Pay attention to hot surfaces such as the engine,
exhaust etc.
• When disassembling the ATV, keep alike parts such as gear pairs, cylinder, piston, etc.
together. When assembling or replacing these components they should be kept in pairs.
• When disassembling the engine, clean all components and place in a tray in the order of
disassembly, not only increasing the assembling speed, but also ensuring the correct assembly.
2. Replace the components
When replacing components use only the products, lubricants and grease recommended by
manufacturer.
3. Oil seal, shim, O-ring, clip, split pin, elastic washer
• When disassembling to maintain the engine, to ensure that the reassembled engine has good
sealing and connected parts are fixed and reliable, the oil seal, shim, o-ring, clip, split pin and
elastic washer should be replaced, be sure to keep lip of oil seal, surface of shim and o-ring in a
clean condition.
• When reassembling, apply lubricant to all the alike components and bearings,
apply grease for oil seal.
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4. Clip
Before assembling, check all the clips carefully.
Replace with a new one after removing from piston
pin. When mounting clip ring (1), make the sharp
end face (2) on the opposite position of
impacted face (3) of clip. (see figure at left)
5. Locking washer/shim and location pin
When reassembling, replace all locking washer/shim
and location pin (a) . After bolt or nut is in the lock
position, bend and fix both ends of locking shim
along head of bolt or direction of nut.
6. Bearing and oil seal
When assembling bearing and oil seal, put the mark
(specification of manufacturer) outside. When as-
sembling oil seal, apply a thin layer of lithium-based
grease on the lip of oil seal.
CAUTION:
Do not dry inside of bearing by blowing out with
compressed air, this will cause damage to the surface
of the bearing.
9
7. Check of electric parts
Make sure there is no rust, dirt or moisture at the
connection, if there is blow it dry or clean.
The electrolyte inside the battery is corrosive, take
extra precautions as to not get this on your body.
When repairing wires on electrical parts, remove
the wire on the terminal of negative pole of battery
(see figure 7.1). When tightening or loosening bolt
on terminal of battery, do not let the wrench contact
the engine or other metal parts of the vehicle body to
avoid electric shock.
When connecting the wire to battery, first connect
the positive pole then connect the negative pole.
After wires are connected, apply clean grease on the
terminal to increase resistance of rust.
Check the terminal of connector
A. Grip the two terminals of connector together,
check with the multimeter (see figures 7.3 and 7.4)
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What's Included?
Lifetime Access
Fast Download Speeds
Online & Offline Access
Access PDF Contents & Bookmarks
Full Search Facility
Print one or all pages of your manual
$32.99
Baja Wilderness (WD400U) Service & Repair Manual is a comprehensive guide for troubleshooting and replacing ATV components. It includes step-by-step instructions, clear images, and exploded-view illustrations, making it suitable for both professional mechanics and DIY enthusiasts.
Regular maintenance is essential for the durability of your ATV. Over time, certain parts will wear out and require replacement. This manual provides manufacturer-recommended troubleshooting charts and procedures, enabling you to save on repairs and enhance your ATV’s reliability.
It is important to note that this is not a generic manual but the official repair manual used by professional technicians. It eliminates the hassle of searching through numerous pages and offers the convenience of digital access, allowing easy navigation, bookmarking, and even printing if desired.
- Printable: Yes
- Language: English
- Compatibility: PC & Mac computers, Android and Apple smartphones & tablets, etc.
- Requirements: Adobe Reader (free)
