Baja motorsports DR90 User manual

DR90/WR90 Dirt Bike
Read this manual carefully. It contains important safety information.
No one under the age of 16 should operate this dirt bike.
Always wear a helmet; It could save your Life!
Do not remove this operator’s manual from this vehicle.
Please obtain, review, and follow provincial / municipal government acts and
regulations pertaining to owning and operating an off-road vehicle.
OWNER’S MANUAL
No one under the age of 16 should operate this Dirtbike without
adult supervision. Parents should consider child’s age, size,
maturity and ability before allowing to ride.
Rev. D
020409

Congratulations on your purchase of the BAJA INC. DR90/WR90 Dirt Bike.
Your bike is warranted to be free of manufacturing defects in the material
and workmanship for a period of 90 days from the date of purchase.
During the warranty period BAJA, INC. will at its option, repair, provide
replacement parts or replace your Baja Motorsports 90cc Dirt bike at
no charge. This warranty does not cover normal wear items or damage
caused by neglect or misuse of the product.
Engine Warranty – 90 days
Frame Warranty – 90 days
Warranty is void if:
Frame is bent or broken due to abuse
Wheels are bent or broken
Fender bent or broken due to abuse
Any sign of impact, accident, jumping, spin-outs or roll over.
BAJA, INC. is not liable for any damage claim or liability claim person or
otherwise resulting from the operation of this product in any way.
Should you experience a problem with your vehicle, please call the Baja
INC. customer service line toll free at 1-888-863-2252 between the hours of
7am and 5pm Monday through Friday MST (Mountain Standard Time). MDT
(Mountain Daylight Time) during daylight saving time. You will be instructed
how to proceed.
A COPY OF THE SALES RECEIPT IS REQUIRED.

This manual should be considered as a permanent part of the
vehicle and should remain with the vehicle when resold or
otherwise transferred to a new user or operator. The manual
contains important safety information and instructions which
should be read carefully before operating the vehicle. All
operators should obtain, review, and follow provincial and
municipal government acts and regulations pertaining to
owning and operating an off-road vehicle. Children under the
age of 16 should never operate this vehicle.
WARNING
!
The engine exhaust from this product contains chemicals
known to the State of California to cause cancer, birth defects
and other reproductive harm.
CALIFORNIA PROPOSITION 65
WARNING
!

SAFE OPERATION..............................................................................................3
SAFETY GEAR....................................................................................................3
MODIFICATION OF VEHICLE.............................................................................3
LOCATION OF WARNING LABELS....................................................................4
PARTS & SUBASSEMBLIES ..............................................................................5
OPERATION ........................................................................................................7
FUEL VALVE................................................................................................7
ENGINE STARTING.....................................................................................8
BREAKING IN THE ENGINE.......................................................................9
SWITCHES ON THE RIGHT HANDLEBAR ................................................10
GEAR SHIFTING .........................................................................................11
CHECK-UPS, ADJUSTMENT AND MAINTENANCE..........................................12
CHANGING THE OIL...................................................................................13
CHECK-UP OF SPARK PLUG ....................................................................13
CHECKING & CLEANING THE AIR FILTER...............................................14
ADJUSTING THE THROTTLE CABLE .......................................................15
ADJUSTING THE CARBURETOR ..............................................................15
ADJUSTING THE AIR VALVE GAP ............................................................16
ADJUSTMENT OF FRONT BRAKE............................................................17
ADJUSTMENT OF REAR BRAKE ..............................................................18
ADJUSTMENT OF CHAIN...........................................................................19
DRIVE CHAIN LUBRICATION.....................................................................19
VEHICLE WASHING....................................................................................20
INSTRUCTIONS FOR STORAGE ...............................................................21
RESUMPTION OF SERVICE AFTER STORAGE .......................................22
TABLE AND TORQUE OF FASTENERS ....................................................22
RESUMPTION OF SERVICE.......................................................................23
MAINTENANCE ROUTINE - DIAGRAM......................................................23
ELECTRICAL - DIAGRAM...........................................................................25
EMISSION CONTROL SYSTEM WARRANTY............................................26
Table of Contents

Please read this manual and follow all instructions carefully. To emphasize special
information, the symbol and the words WARNING or CAUTION have special
meaning. Pay attention to WARNINGS and CAUTIONS.
NOTE: Indicating special information which makes maintenance easier and/or
instructions clearer.
WARNING and CAUTION are arranged like this:
This user’s manual contains important safety and maintenance information. Read
it carefully before riding. Failing to follow the warnings contained in this manual
could result in INJURY or DEATH.
It is important that this manual remain with the vehicle when you transfer it to
another user or owner.
All information, illustrations, photographs and specications contained in
this manual are based on the latest product information available at the time
of publication. Due to improvements or other changes, there will be some
discrepancies in this manual. We reserve the right to make product changes at
any time, without notice and without incurring any obligation to make the same or
similar changes to the vehicle previously built or sold.
WARNING-or-CAUTION
The rst part will identify a POTENTIAL HAZARD.
The second part will describe WHAT COULD HAPPEN if you ignore
the WARNING or CAUTION.
The third part will describe HOW TO AVOID THE HAZARD.
CAUTION
Indicates a potential hazard that could result in vehicle damage.
WARNING
Indicates a potential hazard that could result in death or injury.
!

SAFE OPERATION
Rules for Safe Operation
A pre-operation check must be conducted before starting the engine.
This check will insure safety, prevent mishaps, and prevent damage to
components.
It is strongly suggested that all operators take a certied motorcycle rider’s
course prior to operating the vehicle.
Full attention is required during driving; paying close attention to the
following points to avoid any injury to you by other motorized vehicles:
· Do not drive too close to other vehicles.
· Never carry a passenger. This dirt bike is for one operator only.
· Never operate this dirt bike at night. Night is dened as the period of
time 30 minutes before sunset to 30 minutes after sunrise.
· Driving at high speeds is the cause of many accidents; do not drive at a
speed that the actual situation does not permit.
· Always avoid operating an this dirt bike on paved surfaces, including;
sidewalks, paths, parking lots, driveways, streets, roads, and highways
Never operated this or any Off-Road Vehicle on a public street, road or
highway where motor vehicles are in operation.
SAFETY GEAR
1. Never operate this dirt bike without wearing a DOT approved motorcycle
helmet which ts properly. Operators should also wear eye protection
(goggles or face shield), gloves, boots, long-sleeved shirt or jacket, and long
pants.
2. Loose clothes are not suitable for motorcycle driving or riding as they may
get caught on the operating lever, kick lever, footrest or wheel, resulting in
danger.
MODIFICATION OF THE VEHICLE
CAUTION
Never perform any unauthorized modications to this vehicle. Only use
original replacement part which can be obtained through Baja Inc.
888-863-2252.
!

LOCATION OF WARNING LABELS
Read and follow all of the warnings labels on your Dirtbike. Make sure you
understand all the labels. Keep the labels on the Dirtbike. Do not remove them
for any reason. If a label comes off or becomes difcult to read, you should get a
replacement by contacting Baja Inc.
1
2
!
WARNING
No one under the age of 16 should operate
this vehicle without adult supervision.
!
WARNING
• Study the owner’s manual carefully.
• Always wear a helemt, eye protection and protective gear.
• Never operate this vehicle while under the inuence of
alcohol, drugs or medication of any kind.
1
2

PARTS & SUBASSEMBLIES
Front brake lever
Throttle twist
grip
Fuel tank
cover

Front Wheel
Front Shock Absorber
Fuel Valve
Gear Shifting
Pedal
Engine Number Side Stand Rear Fork
Rear Wheel
Seat Cushion
Exhaust Silencer
Kick Lever Rear Braking Pedal

OPERATION
FUEL VALVE
Fuel lling
The capacity of the fuel tank is 5.2L in total including 1.0L of reserve. Unscrew the
gas cap by turning it counter clockwise and carefully ll the tank with unleaded
gasoline through the opening. DO NOT MIX GAS AND OIL TOGETHER, THIS IS
A 4-STROKE ENGINE. Replace the gas cap by carefully aligning the threads on
the cap and the tank and turning the cap clock wise. Wipe any spilled fuel from
the dirt bike using a cloth and dispose of the cloth properly. DO NOT SMOKE OR
REFUEL THE VEHICLE NEAR OPEN FLAMES OR NEAR HEATING UNITS. ONLY
REFUEL THE VEHICLE IN OPEN AREAS TO REDUCE THE LIKELIHOOD OF THE
BUILD UP OF GASOLINE FUMES.
Operation of the fuel valve (the valve under the fuel tank)
ON: With the handle of the fuel valve to “ON” position, the fuel supply will ow to
the carburetor.
OFF: With the handle of the fuel valve to “OFF” position, the fuel supply is cut off
to the carburetor.
RES: If the fuel level in the fuel tank becomes to low for the engine to stay run-
ning while the fuel valve is in the “ON” position, turn the fuel valve to “RESERVE”.
This will allow engine to begin using reserve fuel supply. You will need to re-fuel
as soon as possible. Once re-fueled, turn fuel valve back to the “ON “ Position
OFF
RES
ON
Fuel Valve Handle

ENGINE STARTING
1. Set the ignition key to “ ” (ON) position.
2. Place transmission in neutral.
3. Ensure that there is fuel in tank.
4. Set fuel valve handle to “ON” or “RES” position.
To start a cold engine:
1. Place choke lever on carburetor up
(to close the choke).
2. Rotate throttle twist grip by 1/8 to 1/4 turn.
3. Start engine with kick start.
4. Slightly turn throttle twist grip to increase speed of engine so as to warm up
the engine.
5. Push carburetor choke lever downward to fully open choke after engine has
sufciently warmed up.
Procedures for stopping the engine:
1. Release throttle twist grip to slow down engine.
2. Shift to neutral position.
3. Set ignition switch to “ ” (OFF) position.
4. Set fuel valve handle to “OFF” position.
CAUTION
The engine can only be started in neutral gear.
Unnecessarily increasing RPM’s to a high level while the dirt bike is in
neutral is harmful to engine.
CAUTION
Verify oil level prior to starting (see page 25)
Starting the engine with low or no oil will damage the engine.
WARNING
Never start the engine in a closed place as the exhausted gas
from the vehicle contains toxic carbon monoxide.
Choke lever
!
!

BREAKING IN THE ENGINE
The rst 600 Miles of operation should be considered the “Break-in” period and
special attention should be paid to the following points:
1. Take special care not to increase the RPM’s of engine while climbing steep
slopes. Never drive your dirt bike continuously for more than 30 miles without
increasing and decreasing the throttle.
2. The engine should be warmed up for 3-5 minutes prior to operation so all
components are lubricated sufciently.
3. The driving speed shall not be over 25 MPH maximum during the rst 300
miles of operation and not over 35 MPH maximum during the remaining 300
miles of the “Break-In” period.

SWITCHES ON RIGHT HANDLEBAR
Ignition switch
The ignition switch is provided on the right handlebar.
When ignition switch is turned to “ ” (off) position, engine will not start. If
engine is running this will stop engine.
When ignition switch is turned to “ ” (on) position, engine can start and the
vehicle can be driven.
ON button
Ignition Switch
OFF button

GEAR SHIFTING
A non-cycling mode of gear shifting is employed for this motorcycle.
Reduce throttle before shifting. Never increase throttle while shifting gears.
Do not place your foot on gear-shifting pedal while operating dirt bike to avoid
damaging the clutch caused by sudden accidental gear shifting.
Legend for the right gure:
(N) Neutral gear
(1) 1st gear
(2) 2nd gear
(3) 3rd gear
(4) 4th gear
Points for Attention during Drive
1. Avoid unnecessary idling of engine at a high speeds. Doing so will damage
engine components seriously.
2. The clutch will wear out quickly if dirt bike is operated with clutch in a semi-
engaged position.
3. Only shift to low speed gears when you feel that there is insufcient power to
climb hills or continue forward.
4. Do not use front brake only or coast using neutral gear especially when
descending or driving at a high speed.
5. Decrease throttle when braking.
Shifting forward
Shifting backward
N 1
24
3
N 1 2 3 4

CHECK-UPS, ADJUSTMENT AND MAINTENANCE
Checking the Oil
Check engine oil each time prior to operating dirt bike.
The oil level should be between the upper and lower lines of oil gauge tted in a
screw plug, which is on right cover of crankcase.
1. Set dirt bike on level ground, screw off oil gage plug, wipe oil gage rod clean
and insert gage plug into crankcase again to check oil level. There is no need
to screw oil gage plug into its hole in crankcase.
2. Add lubricating oil up to the upper line when needed, but do not overll.
3. Finally screw on oil gage plug tightly.
Lubricating Oil Recommended
The lubricating oil is an important factor affecting performance and service life
of engine. Please refer to the chart for correct grade of engine oil based on the
environmental conditions in your area. Do not use any other type of oil other than
what is recommended in the chart. DO NOT MIX OIL WITH THE GASOLINE.
Lubricating oils of different
viscosity should be employed
in different regions and at
different temperatures.
MACHINE
OIL
TEMP.
°C
°F
-30
-22
40
104
-20
-4
-10
14
0
32
10
50
20
68
30
86
20W-50
5W-40 15W-50
10W-40 10W-50
10W-30
CAUTION
Never start engine when there is
insufcient lubricating oil. Otherwise,
it will cause harm to engine.
Machine oil gauge
!

CHANGING THE OIL*
1. Remove “Screw Plug” located at bottom of engine and let oil drain into an
approved collection container. DO NOT PERFORM THIS PROCEDURE WHILE
ENGINE IS HOT. SERIOUS BURNS COULD RESULT FROM CONTACT WITH
HOT OIL.
2. Dispose of used oil properly. For proper disposal procedures, contact your
local oil recycling center.
3. Clean and replace “Screw Plug” tightly.
4. Rell engine with proper amount of oil and recheck amount of oil in engine by
using oil gauge plug.
CHECK-UP OF SPARK PLUG
1. Remove cap of spark plug and screw off
spark plug using plug wrench.
2. Clean spark plug all around or replace
it if it is corroded or there is too much
deposit on it.
3. Regulate the gap of spark plug to
0.6-0.7mm (0.024 in - 0.028 in).
3. The spark plug of designated type
should be used. The applicable type of
spark plug: NHSP LD A7RTC made in
China or Equivalent US Brand.
0.6 mm - 0.7 mm
(0.024 in - 0.028 in)
Screw plug for oil draining

CHECKING & CLEANING THE AIR FILTER
Take air lter out and check if it is dirty or torn.
Dismounting:
Wash lter in clean water and wipe dry with a clean cloth.
Soak lter element in clean machine oil. Squeeze it with a dry cloth to remove
excess oil.
Recommended oil: 15W/40QE
CAUTION
The air lter element must be intact or engine will suck in dust and dirt,
resulting in a shorter service life of engine.
Water should be prevented from entering into lter when washing vehicle.
The lter element should be cleaned gently without twisting to prevent it
from cracking. Never wash it with gasoline or any acid, alkaline or organic
volatile oil to avoid its aging, which will result in reducing the effect of the air
lter oil to catch particles before they enter engine. Replace lter element
with a new one if it is broken or cracked.
Air Filter cover Removal of lterRemoval of cover
Squeeze out excess
water
Wash with water
!

ADJUSTING THE THROTTLE CABLE
Make sure that the adjusting and lock nuts of throttle cable work normally.
Check if throttle twist grip has the required free operating movement.
The required free operating movement: 2-6mm. If grip cannot be moved freely,
turn adjusting nut to ensure proper operating movement.
*After adjustment, start engine and check for operating movement again. Repeat
adjustment if necessary until desired operating movement is obtained.
ADJUSTING THE CARBURETOR
Adjusting procedures of idling speed:
1. Support vehicle by a stand.
2. Adjust idling speed by throttle stop screw to 1500 ± 150rpm.
CAUTION
Do not try to correct a malfunctioning carburetor by adjusting the idling speed. If
carburetor is not functioning properly, it should be repaired by a service center.
Adjust idling speed only when engine is warmed up or 10 minutes after operation.
Idling speed adjusting screw
!

VALVE INSPECTION
REFER TO MAINTENANCE SCHEDULE IN THIS OWNER’S MANUAL FOR VALVE
ADJUSTMENT INSPECTION INTERVALS.
Valve clearance should be:
Intake: 0.002 inch (0.051 mm)
Exhaust: 0.003 inch (0.076 mm)
The engine will make excess noise if the gap is too large in air valve. If gap is too
small valve operation will be hindered which could result in valve malfunction and
failure. Therefore, air valve gap must be checked periodically.
If you have the proper tools and are mechanically procient, instructions on
adjusting the valve clearance are given in the service manual. If assistance is
needed please contact Baja Inc to nd your local service center.

1. Inspect front disk brake caliper for leakage. If brake uid leaks, the safety of
riding could be affected.
2. Inspect brake hose for cracks, and joint for leakage.
3. Check brake uid level in brake uid reservoir, if level is at or below the
LOWER mark, inspect brake pads for wear and hydraulic system for leaks.
4. To add brake uid, unscrew the 2 screws on top of bake uid container. Add
DOT3 or DOT4 brake uid. Do not mix brake uid types.
FRONT HYDRAULIC DISK BRAKE INSPECTION
Brake uid
level
Brake uid cap
Brake hose
Front disk brake
caliper
Brake disk
Lower mark
Brake uid reservoir