Cobra 2007 CX65 User manual

2007
20072007
2007
CX65
CX65CX65
CX65
Owners
OwnersOwners
Owners
Parts
PartsParts
Parts
Service
ServiceService
Service
Tuning
TuningTuning
Tuning

DISCLAIMER OF WARRANTY
This motorcycle is sold “as is” with all faults, obvious or not. There are no warranties
expressed or implied, including any warranty of merchantability and warranty of fitness
for any particular purpose.
“WARNING”
THE COBRA CX65 IS A COMPETITION MODEL ONLY AND IS NOT
MANUFACTURED FOR, NOR SHOULD IT BE USED ON PUBLIC STREETS, ROADS
OR HIGHWAYS.
THE USE OF THIS BIKE SHOULD BE LIMITED TO PARTICIPATION IN
SANCTIONED COMPETITION EVENTS UPON A CLOSED COURSE BY A
SUFFICIENTLY SKILLED RIDER AND SHOULD NOT BE USED FOR GENERAL
OFF-ROAD RECREATIONAL RIDING.
IMPROPER USE OF THIS MOTORCYCLE CAN CAUSE INJURY OR DEATH.
THIS BIKE IS INTENDED FOR EXPERIENCED RACERS ONLY AND NOT FOR
BEGINNERS.
IT IS YOUR RESPONSIBILITY AS THE OWNER OF THIS COBRA MOTORCYCLE
OR AS THE PARENT, OR LEGAL GUARDIAN OF THE OPERATOR, TO KEEP THIS
COBRA MOTORCYCLE IN PROPER OPERATING CONDITION.
THIS BIKE WAS DESIGNED FOR RIDERS THAT WEIGH LESS THAN 80 LBS WITH
FULL RIDING GEAR AND SHOULD NOT BE OPERATED BY RIDERS THAT WEIGH
MORE THAN THAT.
BE SURE THAT THE RIDER ALWAYS WEARS ADEQUATE SAFETY GEAR
EVERYTIME HE OR SHE RIDES THEIR COBRA MOTORCYCLE.
IMPORTANT SAFETY NOTICE
Failure to follow WARNING instructions could result in severe injury or death to
the machine operator, a bystander, or a person inspecting or repairing the
machine.
CAUTION:
A CAUTION indicates special precautions that must be taken to avoid damage to
the machine.
NOTE:
A NOTE provides key information to make procedures easier or clearer.
MCCX6507.1

1
Table Of Contents
GENERAL INFORMATION.......................................................................................3
SPECIFICATIONS -GENERAL..........................................................................................3
OPTIONAL COMPONENTS ..............................................................................................4
SPECIFICATIONS -TORQUE VALUES ..............................................................................5
BREAK-IN PROCEDURE.................................................................................................6
STARTING PROCEDURE.................................................................................................7
MAINTENANCE..........................................................................................................8
TIPS.............................................................................................................................8
SCHEDULE....................................................................................................................8
REPLACING TRANSMISSION /CLUTCH LUBRICANT.......................................................10
CHAIN ADJUSTMENT...................................................................................................11
AIR FILTER CLEANING................................................................................................12
FORK OIL REPLACEMENT ...........................................................................................13
PARTS.........................................................................................................................14
PARTS –AIRBOX &INLET SYSTEM .............................................................................14
PARTS –BARS AND CONTROLS ...................................................................................15
PARTS -CARBURETOR ................................................................................................16
PILOT JET................................................................................................................16
MAIN JET.................................................................................................................16
PARTS –COOLANT SYSTEM ........................................................................................17
PARTS –ELECTRICAL SYSTEM ....................................................................................18
PARTS –ENGINE CLUTCH ...........................................................................................19
Parts – Engine – Clutch / Kick Cover ....................................................................20
Parts - Engine - Ignition Side.................................................................................21
Parts - Engine – Kick Mechanism..........................................................................22
Parts – Engine – Shift Mechanism.........................................................................23
Parts – Engine – Top End......................................................................................24
Parts - Engine - Transmission................................................................................25
PARTS –EXHAUST SYSTEM.........................................................................................26
PARTS –FORKS –LEG ASSEMBLY...............................................................................27
PARTS –FRAME &TRIPLE CLAMPS.............................................................................28
PARTS –FRONT WHEEL &BRAKES.............................................................................29
PARTS –BODYWORK...................................................................................................30
PARTS –REAR BRAKE ................................................................................................31
PARTS –REAR WHEEL................................................................................................32
PARTS –SHOCK..........................................................................................................33
PARTS –SWINGARM ASSEMBLY..................................................................................34
SERVICE.....................................................................................................................35
ENGINE SERVICE........................................................................................................35
Base Gasket Selection............................................................................................36
FUEL &AIR SYSTEM ..................................................................................................39
TUNING ......................................................................................................................42

2
GEARING....................................................................................................................42
SUSPENSION...............................................................................................................43
CARBURETION............................................................................................................44
TROUBLESHOOTING..............................................................................................47
INDEX .........................................................................................................................48

3
General Information
Specifications - General
Items CX65
Dimensions
Wheelbase 40.9” (1040mm)
Wheel size 12” (305mm) rear, 14” (356mm) front
Seat height 29.9” (760mm)
Engine
Type 2-stroke, single cylinder, reed valve
Cooling system Liquid-cooled
Coolant Liquid Performance Mini Coolant or Antifreeze
Displacement 64.9 cc
Bore and stroke 44.5 mm x 41.7 mm
Ignition system Electronic, digital advance
Spark plug Champion 8339-1, 8332-1 hotter, 8904-1 colder
Gap 0.023” – 0.025” (0.58 – 0.64 mm)
Ignition timing Digital advance (set at TDC)
Fuel type High octane pump gasoline
Oil type Cobra Venom 2-cycle Race Oil
Fuel / oil mix ratios Between 32:1 and 40:1 (after engine Break-In)
Carburetion 24 mm VM Mikuni
Main Jet 230
Slow (Pilot) Jet 40
Float Height
Transmission
Speed 6 speed
Final drive ratio 14/48 or 13/46
Chain 116 links 420
Transmission / clutch oil type Quality gear lubricant
Quantity 530 ml (18.0oz)

4
Chassis
Front tire 60/100 – 14
Rear tire 80/100 – 12
Front fork Marzocchi 35mm USD, Compression adjustable
Fork oil type SAE 10 weight
Fork oil amount 210 ml (7.1oz)
Spring Preload Length 178mm (49 N/mm
Rear shock Öhlins: Compression & Rebound Adjustable
Spring rate 280 lb/in (49 N/mm)
Optional Components
Call your dealer, or the factory, for details
•Carburetor jets
•Pre filter for the airbox
•Tires, tubes or ‘Tire Balls’
•Sprockets
oFront
oRear
•Suspension Springs
Weight of Rider (lb) Fork Spring Shock Spring
less than 75 lb 42 N/MM
SCC60240P
75-90 lb 0.23 kg/mm
KCC60024
45 N/MM
SCC60260P
90-100 lb 0.26 kg/mm
KCC60026
49 N/MM
SCC60280P
Greater than 100 0.27 kg/mm
KCC60028
53 N/MM
SCEX1300

5
Specifications - Torque Values
Torque Value
Fastener ft-lb in-lb Nm Size & Remarks
Cylinder head
nuts 12.5 150 17 M7 x 1.0
Crankcase
bolts 8.8 105 12 M6 x 1.0
Spark plug (SP) (SP) (SP) M14 x 1.25
Stator bolts 2.1 25 2.8 M5 X 0.8
Stator cover
bolts 1.7 20 2.3 M4 X 0.75
Clutch cover
bolts 5.8 70 7.9 M6 X 1.0
Clutch nut 35 420 47 M10 x 1.25*
Front axle bolt 10 120 13.5 M14 x 2.0
Front axle
pinch bolt 7.4 88.5 10 M6 X 1.0
Engine mount
bolts 22 265 30 M8 X 1.25
Swingarm
Pivot 21 250 28 M12 X 1.5
Intake manifold
bolts 4.6 55 6.2 M6 X 1.0
Rear Axle Bolt 25 300 34 M14 X 1. 5
Rear Sprocket
Bolts 20 240 27 M8 X 1.25
Triple clamp
bolts 6 72 8 M6 x 1.0
Fork cap 15 177 20
Fork Damper
Nut 11 133 15
Ignition rotor
nut 40 480 54 M10 x 1.25*
* Apply high strength thread locking agent when installing
(SP) To apply the proper torque to the spark plug when inserting, one must first
screw the spark plug in until the metal gasket ring causes resistance and then
turn another 1/8 to ¼ turn.

6
Break-In Procedure
Your Cobra CX65 is a close-tolerance high performance machine and break-in
time is very important for maximum life and performance. The CX65 can be
ridden hard after the first ½ hour break-in time but it is recommended that no
adjustments are made to the carburetion or suspension until the full 8 hours of
bike break-in has elapsed. Also, after the engine, transmission, and drive train
have been broken-in for the full 8 hours, the bike will be faster!
Use a fuel / oil mixture of 32:1 for the full 8 hour break-in period. Be sure to use
high octane pump gas with Cobra’s specially formulated Cobra Venom 2-cycle
Race Oil. (Part # MCMUOL02)
CAUTION:
Failure to use proper fuel, oil, or fuel/oil mixture may result in premature engine
wear or damage to the machine.
Adhering to the following break-in schedule will result in long lasting high
performance machine.
•Start bike on stand
•First 5 minute period, operate the bike on the stand with a combination of idle
and high RPM operation. (avoid prolonged high RPM but spin the rear
wheel good at least once or twice per minute)
•Allow bike to cool
•Ride for 15 minutes maximum (avoid prolonged high RPM operation and
avoid abusing the clutch).
•Cool and inspect bike for loose fasteners.
•Next ½ hour of operation, avoid prolonged operation at Wide Open Throttle.
•After 1 hour of operation
oCheck for loose bolts and nuts on the bike and retighten as
necessary (proper toque values are listed under Specifications).
oClean the carburetor bowl.
oChange the transmission / clutch lubricant.
•After 8 hours of operation
oChange the fork oil.
oHave a Certified Cobra Mechanic change the shock oil.
•Your bike is now ready for the highest level of competition!
NOTE:
During break-in the bike will likely lose some engine coolant through the radiator
overflow hose. Losing up to 4 oz (120 ml, ½ cup) is normal. Proper coolant level
will cover the top of the radiator cores. Removing the radiator cap and looking
inside is the only way to check the coolant level.

7
Never open the radiator cap of a machine that has a hot or warm engine or one
that has recently been ridden. Burning and scalding could occur.
CAUTION:
It is important that the radiator cap is installed correctly and completely otherwise
engine damage could occur.
Starting Procedure
Before starting the machine inspect the following:
•Check for proper tire pressure in both tires.
•Observe the chain tension and adjust if necessary.
•Observe the coolant level and fill if necessary.
•Verify that the chain rollers and sliders do not have improper wear.
•Verify that the handlebars are tight.
•Check the throttle for smooth operation and sound closing.
•Check for loose bolts and nuts, and re-torque as necessary.
•Verify that the air filter is clean and properly saturated with oil.
•Insure that the fuel tank contains an adequate volume of fuel / oil mixture to
complete the distance required. (High octane pump gas with Cobra’s
specially formulated Cobra Venom 2-cycle Race Oil)
•Turn the fuel on by rotating the fuel petcock lever to the vertically downward
position.
CAUTION:
For best results from your Cobra Motorcycle use only the recommended fuels.
‘Race’ fuels can be used, however, they are not required with the stock engine,
and the engine will require addition attention to maintain proper jetting as
weather condition change throughout the day.
Always wear a helmet and other protective riding gear.
When your pre-ride inspection is complete the bike may be started. For a cold
engine follow this procedure.
1. Place the motorcycle on a stand of sufficient strength that positions the
motorcycle in a level upright position with the rear wheel off the ground.
2. Engage the choke by pulling out on the choke button until it stops.
3. Kick start the engine.
4. Rev the engine in short spurts, turning the throttle no more than 1/4 open
until the engine will run without the choke.
5. Verify a functional engine shut-off switch by shutting off the engine.
6. Restart the engine and proceed with riding when the engine is sufficiently
warm (i.e. the side of the cylinder is warm to touch).

8
CAUTION:
Never rev an engine full throttle when it's cold or slightly warmed up. This may
lead to premature wear of engine components or complete cold seizure of the
engine.
CAUTION:
Cobra recommends that you tell your child to take it easy the first couple of
minutes in practice until the engine comes up to full operating temperature.
Maintenance
It is important that you adhere to this maintenance schedule so as to promote the
longevity of your Cobra Motorcycle.
Tips
1. Cobra lubricants:
a. Use only high quality transmission oil designed specifically for two-
stroke racing engines.
b. Cobra Two Cycle Oil exceeds the JASO FD & ISO-L-EGD
specifications, which are the world’s most stringent requirements on
lubrication, detergency, and smoke.
2. Fill your transmission only with the recommended amount of oil. Overfilling
may lead to premature seal failure.
3. The cylinder base gasket has been ‘fitted’ for your engine. See the service
section of this manual for instructions how to properly size a base gasket
during an engine rebuild.
4. Evaluate the bikes jetting only after it has been warmed up to race
temperatures.
5. A properly maintained machine is safer, faster, and more fun to ride.
6. New chains will stretch on first use. Never install a new chain prior to a
race. Always ‘break’ them in during practice.
7. Your Cobra Motorcycle has a 10 digit VIN (Vehicle Identification Number).
The first two digits indicate the model and the seventh indicates the model
year (MY).
a. Example, CXxxxx7xxx is a 2007 MY CX65.
Schedule
•Between each ride
oCheck the air filter (clean and re-oil as necessary).
oInsure the smooth operation of the throttle cable (throttle soundly
‘clacks’ shut).
oCheck for frayed strands of the throttle cable inside the throttle housing
and replace if necessary.
oCheck for adequate tire pressures and adjust if necessary.
oCheck all nuts and bolts for proper torque and re-torque if necessary.