Page 2
For parts orders contact your local dealer To locate your closest Cobra dealer log on to www.cobramotorcycle.com or call (330) 549-9600 If you need technical assistance contact your local dealer or call the Cobra Technical Support Hotline at (330) 549-9603 Cobra Motorcycle MFG., Inc.
Page 3
THIS BIKE IS INTENDED FOR EXPERIENCED RACERS ONLY AND NOT FOR BEGINNERS. IT IS YOUR RESPONSIBILITY AS THE OWNER OF THIS COBRA PRODUCT OR AS THE PARENT, OR LEGAL GUARDIAN OF THE OPERATOR, TO KEEP THIS COBRA PRODUCT IN PROPER OPERATING CONDITION.
Table Of Contents General Information ......................5 Specifications - General....................5 Specifications - Torque Values ..................6 Optional Suspension Components ................7 Break-In Procedure ......................8 Starting Procedure .......................9 General Tips........................10 Maintenance........................11 Schedule & Tips ......................11 M1: Replacing Transmission Lubricant..............12 M2: Chain adjustment....................13 M3: Air Filter Cleaning ....................14 M4: Front end ......................15 Toe in adjustment ....................15 Steering ........................15...
Page 5
Parts – Engine – Clutch / Kick Cover ....Error! Bookmark not defined. Parts - Engine - Ignition Side......Error! Bookmark not defined. Parts - Engine – Kick Mechanism..... Error! Bookmark not defined. Parts – Engine – Shift Mechanism ....Error! Bookmark not defined. Parts –...
Torque Value Size & CHASSIS Fastener ft-lb in-lb Remarks Handle bar mounts 8 x 1.25 Handle bar clamps 8 x 1.25 Front engine mount 8 x 1.25 Rear brake lever pivot 13.6 8 x 1.25 Upper shock mount 10 x 1.5 Lower shock mount 10 x 1.5 Swingarm pivot...
Clean the carburetor bowl. Change the transmission / clutch lubricant. Replace the fuel filter. • After 8 hours of operation have a Certified Cobra Mechanic change the shock oils. • Your bike is now ready for the highest level of competition!
(i.e. the side of the cylinder is warm to touch). CAUTION: Never rev an engine full throttle when it's cold or slightly warmed up. 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.
General Tips Always wear a helmet and other protective riding gear. 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. Make sure your riders’ foot is not resting on the rear brake pedal while they...
The frame is a low carbon alloy tubing and it is important to weld it with the proper rod and heat settings set as light as possible. Cobra recommends replacing the frame with a new one if the old one becomes damaged.
Figure 1 4. After it has drained, reinstall the plug, being sure that the gasket is in place. 5. Reapply oil from oil fill plug 235 cc (8.0 oz) Cobra Venom 3 Shoe Clutch Milk thru the oil fill plug.
CAUTION: Cobra has spent considerable time and money developing the proper lubrication to handle the harsh environment of the automatic clutch and transmission of this motorcycle. Cobra’s specially developed Cobra Venom 3 Shoe Clutch Milk (Part # MCMUGF01) was formulated to provide superior lubrication and cooling capability over extended periods of time and is the recommended lubricant for your Cobra motorcycle.
CAUTION: Be sure to remove the pin from the eccentric before riding. M3: Air Filter Cleaning This Cobra Motorcycle comes with a unique air filter / air boot unit designed to facilitate motorcycle service. Tools recommended for air filter maintenance: •...
Figure 3 Steering The unique Cobra front end will exhibit some free play from the factory and that the seals (it that’s what you want to call them) will fall out after the first ride. We have found that this causes no adverse effects and that the looseness does not get significantly worse as long as the bearings are sprayed with a spray lubricant (WD40 or similar) upon each ride.
Parts Parts – Air Inlet System Figure 4 Coolant System REF # PART # DESCRIPTION RCMU0403 FILTER ASSEMBLY MCKGHO01 HOSE CLAMP – BOOT TO CARB RCCM1301 VELOCITY STACK RCKG0021 CARBURETOR, 21MM DELL’ORTO PHBG MCKGHO04 HOSE CLAMP – CARB TO MANIFOLD HCBC0625 M6X25 SOCKET HEAD CAP SCREW HCWF0601...
Parts - Carburetor Carburetor REF. # PART # DESCRIPTION RCMU0305 CARB SLIDE RCMU0601 NEEDLE RCMU00 ATOMIZER 2.62 AU RCMU0096 MAIN JET RCMU0065 PILOT JET CHOKE JET RCMU0301 FLOAT RCMU0102 RUBBER CABLE CAP SEAL RCMU0003 CABLE ADJUSTOR RCMU0006 TOP CARB SCREW RCMU0106 CARB TOP ZCMU0007...
Parts – Coolant System Figure 9 Coolant System REF # PART # DESCRIPTION FCEX0001 RADIATOR WITH CAP FCMU0047 RADIATOR CAP (2 ears or ribbed) ECEX0010 RADIATOR HOSE, TOP ECEX0010 RADIATOR HOSE, BOTTOM MCEXGR01 GROMMET, BOTTOM RAD MOUNT (2 REQ’D) FCEX0026 PAD, RADIATOR (2 REQ’D) SHOWN HCBF0616...
Parts – Electrical System Figure 10 Electrical System REF # PART # DESCRIPTION IAMU0005 COIL W/SPARK PLUG CAP (3 WIRE) ECMU0065 SPARK PLUG, CHAMPION (8339-1) ECMU0067 OPTIONAL HOTTER PLUG (8332-1) ECMU0066 OPTIONAL COLDER PLUG (8904-1) ICEX0002 TETHER, IGNITION SHUT OFF HCBC0516 SCREW, M5 X 16 (2 PER) HCCN0000...
Page 23
Parts – Engine – Bottom End and Transmission Figure 7A Engine Bottom End and Transmission REF # PART # DESCRIPTION ECKG0032 CRANKCASE, IGNITION SIDE no bearings ECKG0033 CRANKCASE, CLUTCH SIDE, no bearings ZCMU0601 GASKET, CRANKCASE CENTER HCBC0605 6X40MM SOCKET HEAD CAP SCREW (6 REQ’D) HCBC0608 6X55MM SOCKET HEAD CAP SCREW (1 REQ’D) HCBC0606...
Parts – Engine Clutch and Kicker Figure 7B Engine – Clutch and Kick Starter REF # PART # DESCRIPTION CAMU0005 CLUTCH COMPLETE CAMU0013 CLUTCH SHOES (SET OF 3) WITH BOLT & WASHERS CCMU0029 CLUTCH ARBOR CAMU0010 SPRINGS, WASHER & BOLT (SET OF 3) HCBS0004 CLUTCH BOLT (3 REQ’D) ECMU0018...
Page 25
Parts – Engine – Ignition and Water Pump Figure 7C Engine – Ignition and Water Pump REF # PART # DESCRIPTION EKMU0001 WATER PUMP KIT ECKG0142 SHAFT, WATER PUMP ECKG0072 BEARING, WATER PUMP ECKG0074 SEAL, WATER PUMP SHAFT ECKG0073 IMPELLER, WATER PUMP ECKG0004 RETAINER, WATER PUMP ASSEMBLY HCBB0003...
Parts – Engine – Top End Figure 7D Engine – Top End REF # PART # DESCRIPTION ECMU0052 CYLINDER ZCKG0501 BASE GASKET ECMU0060 PISTON KIT ECMU0055 PISTON RINGS (2 PER SET) ECMUSR00 SNAP RING FOR PISTON (2 REQ'D) ECKG0012 WRIST PIN ECMU0077 BEARING, WRIST PIN ZCMUOR07...
Parts – Exhaust System Figure 18 Exhaust System REF # PART # DESCRIPTION XCEX5006 2006 ECX50 EXHAUST PIPE ZCMOTE11 HEADER PIPE O-RINGS (2 REQ’D) XCMU0005 EXHAUST SPRING - SHORT NOT SHOWN MCMUGR06 PIPE GROMMET MALE NOT SHOWN MCMUGR07 PIPE GROMMET FEMALE...
Parts - Front A-Arms & Steering Upright Figure 19 A-arms & steering upright REF # PART # DESCRIPTION GAEX0001 A-ARM FRONT TOP (SAME PIECE FROM LEFT TO RIGHT) GAEX0002 A-ARM BACK TOP (SAME PIECE FROM LEFT TO RIGHT) GAEX0007 A-ARM FRONT BOTTOM RIGHT GAEX0006 A-ARM FRONT BOTOTM LEFT GAEX0009...
Parts – Front Brakes Figure 20 Front Brakes REF # PART # DESCRIPTION BAEX0001 FRONT BRAKE ASSEMBLY HOSE – TEE TO CALIPER BRAKE LEVER BCEX0005 BRAKE PERCH & MASTER CYLINDER ASSY W/ LEVER BCEX0003R CALIPER – FRONT RIGHT BCEX0003L CALIPER – FRONT LEFT BCMU0203 REPLACEMENT BRAKE PADS BCEX0002...
Parts – Miscellaneous If you couldn’t find it in one of the other pictures try the table below. PART # DESCRIPTION WCEX0007 REAR WHEEL WITH TIRE 6X8” WCEX0004 FRONT WHEEL WITH TIRE FAEX2006 FRAME FCEX0002 CHAIN SLIDER SPLIT BUSHING HCBH0804 M8 X 120 (FRONT ENGINE MOUNT BOLT) HCWF0801 8MM FLAT WASHER HCNL0801 8MM LOCK NUT...
Parts – Plastic Bodywork & Seat igure 22 Plastic and Bodywork REF # PART # DESCRIPTION TCEX0001 FRONT CLIP NOT SHOWN HCBB0616 M6 X 16 BUTTON HEAD (4 REQ’D AT BACK) NOT SHOWN HCWF0601 6 MM FLAT WASHER (4 REQ’D AT BACK) NOT SHOWN HCBB0620 M6 X 20 BUTTON HEAD (2 REQ’D AT FRONT)
Parts – Tie Rod Assembly Figure 27 Tie Rod Assembly REF # PART # DESCRIPTION FCEX0015 TIE ROD MCEXBR02R RH TIE ROD END MCEXBR02L LH TIE ROD END HCNJ120L RH JAM NUT HCNJ120R LH JAM NUT GCEX0002 SPACER, BALL JOINT HCNC0010 10MM CASTLE NUT (2 REQ’D) HCCP0003...
Page 38
• There appears to be a wide range of variability in reading compression gauges across the country. • The head volume of this Cobra Motorcycle is very small and so requires many kicks ~20 before you establish the most accurate reading possible.
dropped to 90% of its original value the engine will be down on power and would benefit from a rebuild. When it’s dropped to 80% it really needs rebuilt! Using the table below will help you determine monitor the condition of your top end. Engine is Fresh Engine Down on Power Engine NEEDS Rebuilt...
Page 40
7. Remove the special nut / starter gear that holds on the clutch (special tool available, contact your local dealer). 8. With the Cobra flywheel / clutch puller (#MCMUTL68), remove the clutch from the crankshaft (details in Clutch Service portion of this manual).
Page 41
INSPECTION NOTE: Inspect the cylinder head for deposits and abrasions. 1. If there are deposits they should be removed a. Black oily deposits (indicating a rich mixture or improper oil type/quantity) can be removed with solvent b. Crusty deposits (indicating dirt ingestion) can be removed with solvent and may require some scraping.
CAUTION: Take caution when handling the crankshaft. It is the main power transfer to the rest of the engine. If it is out of alignment, it will cause premature failure of your bearings which can lead to serious damage to the cylinder as well as the rest of the engine.
Page 43
9. Torque to 12 Nm (105 in-lb) in the pattern shown in figure 28. 10. Trim away any excess gasket material if necessary. NOTE: Check engine mount holes for excess material that may cause problems in engine installation. 11. Install the piston with new wrist pin bearing and, pin and clips. CAUTION: Be sure to align the piston such that the arrow on the top piston surface points to the exhaust (front of bike/engine) and put assembly lube on the connecting rod...
Page 44
Clutch CAUTION: The clutch components (arbor, shoes, bolt, and belleville washers) on your 2006 Cobra are similar looking but different in geometry from prior years. Do not mix old and new parts as damage will occur. Cobra clutch puller assembly:...
Page 45
Generally reassemble the springs as you removed them from the engine or as you received them from Cobra. This will be either a 3, 4 ½ or, 5 stack. If you are unsure call the Cobra Technical Support Group 330 549 9600, and consult the experts.
Page 46
0.79mm (0.031”) Clutch adjustment washers Your Cobra comes stock with a single flat washer at the bottom of the spring washer stack. The thickness of that flat washer is 0.031” (0.79mm). Cobra offers several thicknesses of thin adjustment washers that allow clutch engagement tuning.
• The best way to prevent glazing is by not gearing too high, changing the oil as specified and by not blipping the throttle. Every time you blip the throttle, you are working your clutch springs. CAUTION: The clutch produces a tremendous amount of heat and when a rider is blipping the throttle.
Page 48
1. After cleaning or replacing the spring washers, reassemble the stack up of washers. CAUTION: It is important to reassemble the washer stack to that which is recommended or to your own specialized stack. CAUTION: It is also important that all three shoes are stacked the same. (See figure 32) 2.
Page 49
Using one hand rotate the kick lever to ½ stroke and hold while tightening the six screws completely with the other hand. 8. Fill with oil (235 ml (8.0 oz) Cobra 3 Shoe Clutch Milk (Part # MCMUGF01). Ignition Stator care Stator failure will result from running the bike hot.
Page 50
CAUTION: Advancing the ignition timing will cause the engine to run hotter, in-turn causing power loss, shortened clutch life, and possibly lead to premature stator failure, and can also cause detonation which can lead to premature piston and ring failure. Tools recommended for timing service: •...
The air stream running through the radiator cools the radiator fluid. Therefore dirty radiators additionally reduce the cooling effect. Cobra has tested numerous brand name automotive and racing coolant / antifreeze solutions and has found Liquid Performance Propylene Glycol based Mini Coolant or Antifreeze to have the greatest effect on reducing cylinder head temperatures.
Page 52
• 3/8” diameter x 8” long steel rod • Hammer COBRA IMPELLER SERVICE INSTRUCTIONS 1. Remove exhaust pipe and gas tank (you may be using a propane torch in step 2. Remove radiator cap and drain engine coolant by removing the 13mm- hex head coolant drain plug.
Page 53
Figure 39 CAUTION: Too much heat can be detrimental to the engine cases. 13. The shaft assembly is serviceable. Use a 4mm hex key to remove impeller retainer screw. Remove impeller, seal and both bearings. Check shaft for wear in the area of the seal.
Page 54
16. Re-assemble in reverse order of disassembly. CAUTION: Clean all threads and use blue (medium strength) thread locker on the belt retainer screw. NOTE: Apply U ltra black Hi-Temp RTV silicon or Teflon pipe sealant to the tapered pipe threads of the coolant fitting before assembly. NOTE: Refill the coolant system with Liquid Performance Propylene Glycol based Mini Coolant / Antifreeze.
Page 55
RCMU0269 VELOCITY STACK Figure 42 Your Cobra is equipped with an adjustable carburetor. Some fine-tuning may be needed according to weather condition and altitude. Proper jetting is very important for engine performance and engine life. Serious damage to the engine can occur if not properly adjusted.
Page 56
adjustment. To lower the idle, turn the screw counter-clockwise. TOP END JETTING: Indications that the engine is running too rich (too much fuel for the air) are: • Engine not revving out or blubbering at high RPMs. • Engine will not ‘clean out’ •...
Page 57
Clean the carburetor in a well-ventilated area, and take care that there is no spark or flame anywhere near the working area; this includes any appliance with a pilot light. Because of the danger of highly flammable liquids, do not use gasoline or low flash-point solvent to clean the carburetor.
Page 58
Reeds: • The reeds must lay flat on the reed cage. • If the reed tips aren’t lying flat, replace them immediately. • The reeds must have a tight seal on the reed cage. • If the reed is damaged in any way, replace it. This means cracks, chips, and ruptures.
Page 59
Tuning Gearing For a bike with a centrifugal clutch, it’s better to be geared too low than too high. What happens with improper gearing? • Poor performance • Not enough top end speed • No snap • Over heat clutch •...
Page 61
Symptoms of improper jetting are listed below. • Symptoms of incorrect oil or oil / fuel ratio o Poor acceleration o Misfire at low engine speeds o Excessive smoke o Spark plug fouling o Excessive black oil dripping from exhaust system •...
Page 62
TOP END JETTING: Adjust for clean full throttle acceleration Jet your top end (main jet) based on the acceleration of your Cobra Motorcycle on the longest straight at the track. Observe any of the lean or rich symptoms (spark plug appearance and bike performance) listed above and change your jetting accordingly.
Troubleshooting 1) Engine not behaving properly a) Carburetor top is installed backwards (happens a lot) b) The carburetor slide indexing pin is missing 2) Engine is down on power a) Clutch engagement is not set properly b) Jetting is incorrect c) Silencer needs repacked d) Exhaust pipe Has excess carbon buildup...
Page 64
Index A-arms..........32 Frame Parts........35 Air Filter..........17 Front Brake........33 Maintenance........14 Fuel Axle .............38 Petcock ..........10 Bars and Controls ......18 Fuel System Break-In..........9 Parts list .........42 Bumper..........19 Service ...........42 Carburetion Gas Tank ...........36 Specifications ........5 General Tips........11 Carburetor .........20 Grab Bar ..........19 Chain Hardware Adjustment........13...
Page 65
Radiator ..........22 Steering Upright........32 Rear Brake Swingarm Parts ........40 Parts ..........37 Throttle ..........17 Rear Drive..........38 Tie Rod..........41 Rear Shock Tips .............11 Parts ..........39 Toe In Adjustment ......16 Reeds ..........42 Top End Parts ..........17 Parts ..........29 Rings ..........29 Torque Seat ............36 Chassis ..........7 shift drum ...........30 Engine ..........6...
Need help?
Do you have a question about the 2006 ECX50 and is the answer not in the manual?
Questions and answers