For parts orders contact your local dealer To locate your closest Cobra dealer log on to www.cobramotorcycle.
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 CX50JR IS A COMPETITION MODEL ONLY AND IS NOT MANUFACTURED FOR, NOR SHOULD IT BE USED ON PUBLIC STREETS, ROADS OR HIGHWAYS.
Table of Contents General Information .............................................................................................. 4 Specifications - General .................................................................................... 4 Optional Suspension Components .................................................................... 5 Specifications - Torque Values.......................................................................... 5 Break-In Procedure .....................................
Parts – Plastic & Seat...................................................................................... 35 Parts – Rear Brake .......................................................................................... 36 Parts – Rear Wheel ......................................................................................... 37 Parts – Shock .................................................................................................. 38 Parts – Shock - Inside ....................................
General Information Specifications - General Items Dimensions Wheelbase Wheel size Seat height Engine Type Cooling system Coolant Displacement Bore and stroke Ignition system Spark plug Gap Ignition timing Fuel type Premix Oil type Premix oil ratio after break-in Carburetion Slow (Pilot) Jet / Main Jet Float Height Transmission Speed / Clutch Final drive ratio Chain Transmission / clutch oil type Quantity Chassis Front tire Pressure Rear tire Pressure Front fork Fork oil type Fork oil amount Std settings Re
Optional Suspension Components Weight of Rider (lb) Fork Spring Shock Spring Less than 38 (light) KCCJ3218 (18 lb/in, 3.15 N/mm) SCMUOH04 (275 lb/in) red 38 – 45 (std) KCCJ3221 (21 lb/in, 3.70 N/mm) SCMUOH05 (285 lb/in) yellow 46 to 55 (stiff) KCCJ3225 (25 lb/in, 4.40 N/mm) SCMUOH06 (295 lb/in) white Specifications - Torque Values Fastener Torque Value Size & Remarks ft-lb in-lb Nm Cylinder head nuts 10.3 123 14 M7 X 1.0 Crankcase bolts 8.8 105 12 M6 x 1.
Break-In Procedure Your Cobra CX50 JR is a close-tolerance high performance machine and breakin time is very important for maximum life and performance. The CX50 JR can be ridden hard after the first ½ hour break-in time. Cobra recommends Bel-Ray H1-R premix oil with high octane pump gas mixed at 40:1 (150 ml oil to 2 gallons of gas). Other brands of oil should be mixed at 32:1 for break-in.
Starting Procedure Before starting the machine inspect the following: Tire pressure Chain tension Coolant level Proper wear on chain rollers and sliders Handlebar tightness Throttle assembly movement/cable adjustment Air Filter Check for loose nuts and bolts Turn the fuel on by rotating the fuel petcock knob to the vertically downward position (reserve position is horizontally forward) NOTE: For best results from your Cobra Motorcycle use only the recommended fuel.
Maintenance A properly maintained machine is safer, faster, and more fun to ride. It is important that you adhere to this maintenance schedule so as to promote the longevity of your Cobra Motorcycle Tips 1. 2. 3. 4. 5. 6. 7. Recommended lubricants: a. Cobra Clutch Milk is by far the best auto clutch lubricant. It is a full synthetic lubricant that has been specifically formulated for Cobra’s auto clutch and has; Exceptional film strength over petroleum based oils or synthetic blends.
8. If you ever need to weld anything on the bike, disconnect the spark plug cap, unplug the ignition, disconnect the kill switch, scrape the paint bare near the area to be welded and put the ground clamp as close to the area to be welded as possible. Be sure the fuel tank and carburetor have been removed and safely located away from the welding process. 9. The frame is 4130 Chrome Moly and it is important to weld it with the proper rod and heat settings set as light as possible.
Replacing Transmission / Clutch Lubricant Tools needed: 5mm allen wrench Minimum of 235 ml (8 oz) Cobra Venom 3 Shoe Clutch Milk (Part #MCMUGF32). Procedure: 1. Begin this procedure with a bike that has been ridden more than 5 minutes but less than 10 minutes. It is desired to have the engine warm enough so that the oil is ‘runny’ but not so hot that there is risk of being burned by the engine or the oil. Hot oil and hot components on the motorcycle may cause burns. 2.
Proper Chain adjustment Tools required for chain adjustment 19 mm wrench or socket 13 mm wrench or socket 1. Make sure that the rear wheel is aligned properly. 2. A properly adjusted chain will have 50mm (13/8”) free movement behind the chain block with no load on the bike. (figure 2) Figure 2 3. Sit on the bike and verify that the chain has a minimum of 12mm (1/2”) free movement when the chain is at its tightest point. 4.
CAUTION: Use only DOT 4 brake fluid Setting rear brake pedal position (see figure 2b): 1. Loosen the lock nut (10mm wrench). 2. Adjust the brake lever stop (10mm wrench) so that the lever is comfortably reachable in both: a. Standing riding position, and Figure 2b b. Sitting riding position. 3. Tighten the lock nut (10 mm wrench). CAUTION: Adequate pedal free play is required so that the brake pads do not drag on the rotor. 1” MINIMUM.
Brake Bleeding Procedure Tools Required: Front: T10 Torx bit/driver, Cobra bleed kit (BCKG0031) Rear: 3mm hex key (Allen wrench, T10 Torx bit/driver, Cobra bleed kit(BCKG0031) Procedure: Remove the brake fluid reservoir cover. Fill the syringe half full with brake fluid. Remove the brake caliper bleed screw. Attach the syringe to the brake caliper bleed access. Keep the syringe oriented as not to allow air from the syringe into the system. Using the syringe pull fluid through the system.
Air Filter Cleaning Tools recommended for air filter maintenance: #2 Phillips head screwdriver 4 mm Allen wrench Foam filter oil Procedure 1. Removed the seat with a 4 mm Allen wrench. 2. Remove the filter/air inlet boot from the back of the carburetor with a Phillips screwdriver 3. Pull the filter / boot assembly out the top of the air box. 4. Clean the filter in a nonflammable solvent to remove the filter oil. Do not clean the air filter with gasoline or other highly volatile petroleum product.
Fork Maintenance Cobra strongly recommends that a professional service technician conduct all internal maintenance other than changing springs and oil. This will help to ensure safe and consistent operation.
Disassembly procedure 1. Remove the front wheel (19 mm wrench). 2. Remove the brake caliper from the fork leg (4 mm hex key). 3. Loosen the fork caps (32mm fork cap tool). 4. Remove the fork legs from the triple clamps (5 mm hex key). 5. One leg at a time a. Remove the fork cap from the fork tube. b. Pull the fork spring down to gain access to the fork cap jam nut and secure it with a 9/16 wrench. c. Holding in one hand the 9/16 wrench use the fork cap wrench to unscrew the fork cap from the damper rod. d.
The slip torque value should be above 60 ft-lb (81 Nm) measured at the sprocket. To properly measure the minimum torque at which the CFD (Cobra Frictional Drive) slips 1. Access the slip clutch by draining the oil and removing the cover exposing the CFD. 2. Brace the CFD gear from turning with a suitable device (Cobra tool EAMU0004 or similar). 3.
Parts Parts – Airbox and Inlet System Airbox and Inlet System REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 PART # ZCCS0001 ECMU0246 RCCS0002 HCWF0601 HCBC0603 MCKGHO04 RCCM0001 RCCM1301 MCKGHO01 RCCJ0004 RCMU0405 TCCJ0004 HCBB0612 RCMU1407 ECCS0030 FCMU0026 MCMUCL04 RCMU0022 DESCRIPTION GASKET – REED TO CYLINDER REED CAGE ASSEMBLY WITH REEDS VFORCE INLET MANIFOLD 6mm FLAT WASHER M6X30mm SOCKET HEAD CAP SCREW HOSE CLAMP – CARBURETOR TO MANIFOLD CARBURETOR 14mm VELOCITY STACK HOSE CLAMP – AIR BOOT TO
Parts – Bars and Controls Bars and Controls REF # 1 2 3 4 5 6 7 8 9 10 11 11A PART # TCMU0008 FCMU0066 FCPW0004 FCMU0021 FCMU0019 BAKG0003 FCMU0033 HCBC0803 HCBC0825 TKMU0404 TKMU0403 DESCRIPTION HANDLEBAR - ALUMINUM GRIPS (SET OF TWO) – SCOTT WAFFLE THROTTLE ASSEMBLY CABLE COVER THROTTLE COVER THROTTLE CABLE BRAKE ASSEMBLY FRONT KILL SWITCH ASSEMBLY M8X30mm SOCKET HEAD CAP SCREW (4) REQ’D M8X25mm SOCKET HEAD CAP SCREW (4) REQ’D BAR MOUNT KIT, SHORT (1 REQ’D) STANDARD BAR MOUNT KIT, TALL (1 REQ’D) ACCES
Parts - Carburetor Carburetor REF.
Parts – Coolant System Coolant System REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 PART # FCCJ0004 MCMUHO02 MCMUCL07 EACJ0001 HCBC0608 HCNL0601 MCKGGR00 MCCMHO01 TCCJ0001 FCMU0049 MCMUCL05 ECHA0109 HCBC0665 FCCJ0002 HCCN0000 HCBC0501 FCMU0022 DESCRIPTION RADIATOR WITH CAP RADIATOR HOSE LEFT HOSE CLAMP MOUNTING BRACKET – RADIATOR BOTTOM M6X55mm SOCKET HEAD CAP SCREW M6 LOCK NUT GROMMET – RADIATOR MOUNTING RADIATOR HOSE RIGHT BUMPER – RAD BRACKET OVERFLOW HOSE – 20” HOSE CLAMP, OVERFLOW HOSE MOUNTING BR
Parts – Electrical System Electrical System REF # 1 2 2A 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ACCESSORY PART # ICCJ0001 ECMU0010C ECMU0010I FCMU0033 HCBH0502 HCWF0501 HCWP0002 HCNL0501 ICMU0018 HCBC0535 HCBC0525 HCWF0504 ICMU0036 ECKG0042 HCNS1001 ECCS0001 ZCCS0002 HCBC0402 ICMU0012 ICMU0017 DESCRIPTION COIL W/SPARK PLUG CAP SPARK PLUG, AUTOLITE COPPERLITE SPARK PLUG, AUTOLITE IRIDIUM KILL SWITCH ASSEMBLY M5X16mm HEX HEAD SCREW (2 REQ’D) 5mm WASHER (2 REQ’D) 5mm WASHER SPECIAL (2 REQ’D) M5 LOCKNUT (2
Parts – Engine – Bottom End and Transmission Engine Bottom End and Transmission REF # 1&2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 23 23 23 24 25 26 27 PART # EKCS0003 ZCCS0005 HCBC0605 HCBC0608 HCBC0606 ECMU0057 ECMU0016 ECMU0118 HCDP1401 DECMU0999 ECMU0100 ECMU0001 ECKG0031 HCBH0612 HCWF0316 ECMU0020L ECKGBR01 ZCDCOR01 ECMU0072 ECMU0073 ECKGSR03 PCKG0013 PCKG0012 PCKG0014 PCKG0015 HCBH0805 HCWC0000 ECMU0233 ECMU0577 DESCRIPTION ENGINE CASE SET W/B&S 50 2012 GASKET, CRANKCASE CENTER M6X40
Parts – Engine Clutch and Kicker Engine – Clutch and Kick Starter REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 PART # CAMU0006 CAMU0013 CCMU0005 CAMU0010 HCBS0004 ECMU0018 CCMU0007 ECMU0120 ECMU0119 ECMU0040 ECMU0132 ECMU0306 ECMU0249 ECMU0305 ECMU0301 ECMU0308 ECMU0307 HCCP0002 EAMU0001 ECMU0116 ZCMUB014 HCWS1622 ECDC0036 EAMU0011 ECMU0250 HCFH0625 ECMU0115 ZCMU0030 ECMU0168 ZCMUB014 HCBC0608 ECMU0207 ECMUSP01 DESCRIPTION CLUTCH COMPLETE CLUTCH SHOES (S
Parts – Engine – Water Pump Engine – Water Pump REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 PART # EKMU0011 ECKG0142 ECKG0072 ECKG0074 ECKG0073 HCBC1512 ECMU0167 ECKG0175 ECMU0180 HCBS0003 ECKG0170 ECKG0042 HCNS1001 HCBC0408 HCWF0401 DESCRIPTION WATER PUMP KIT WITH IMPELLER SHAFT, WATER PUMP BEARING, WATER PUMP SEAL, WATER PUMP SHAFT IMPELLER, WATER PUMP (ALUMINUM) M5X12mm SOCKET HEAD CAP SCREW (STAINLESS) BEARING –WATER PUMP BIG WATER PUMP PULLEY, FAN TYPE – DRIVEN BELT RETAINER SHOULDER BOLT 6mm WATER PU
Parts – Engine – Top End Engine – Top End REF # 1 2 2 2 2 2 2 3 3 3 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 ACCESSORY ACCESSORY PART # ECCJ0001 ZCMU0011 ZCMU0703 ZCKG0501 ZCMU0705 ZCMU0706 ZCMU0708 ECMU0060A ECMU0060B ECMU0060C ECMU0060D ZCMOTE11 ECMU0155 ECMUSR00 ECKG0012 ECMU0077 ZCMUOR07 ECMU0086 HCBC0612 HCNS0703 HCWS1401 ECMU0530 ZCMUOR02 ZCMUV024 ZCMUOR10 ECCS0017 ZCMUOR05 ECMU0147 ZKMUOR11 ZKCSTE11 DESCRIPTION CYLINDER (INCLUDES PISTON, RINGS, PIN & CLIPS) BASE GASKET (0.
Parts – Exhaust System Exhaust System REF # 1 2 3 4 5 6 7 8 9 10 ACCESSORY PART # XCCJ2009 ZCMOTE11 XCMU0005 MCMUGR02 XCMU0028 XCMU0032 MCMUGR03 TCKG0001 HCWF1478 HCBF0625 XCMU0026 DESCRIPTION CX50JR EXHAUST PIPE HEADER PIPE O-RINGS (2 REQ’D) EXHAUST SPRING - SHORT GROMMET KIT PIPE / SILENCER SEAL SILENCER MOUNTING GROMMET (2 REQ’D) SPACER (2 REQ’D) SILENCER GROMMET WASHER (2 REQ’D) M6X25mm FLANGE HEAD BOLT (2 REQ’D) SILENCER PACKING KIT 27
Parts – Forks & Triple Clamps Front Forks and Triple Clamps REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 13A 14 15 16 17 18 19 20 21 22 PART # KACJ0001 KCMU0011 TCC60019 HCBC0601 BCC60015 HCBC0612 HCNL0601 FACJ0004 FCCJ2005 HCNJ0102 HCBC0806 HCBC0820 TKMU0404 TKMU0403 FCMU1103 SCMU0036 FCMU0023 FCMU0024 FCMU0004 HCBC0625 HCBF0616 HCBC0825 FCMU0011 DESCRIPTION FORK ASSEMBLY FORK LEGS ONLY FORK GUARD SET WASHER FORK GUARD (4 REQ’D) M6X16mm, SOCKET HEAD CAP SCREW (4 REQ’D) BRAKELINE CLAMP M6X12mm, SOCKET HEAD CAP SC
Parts – Forks – Leg Assembly – Brake Side REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 15 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 333 33 34 35 36 37 38 PART # DESCRIPTION HCBC0408 ZCKG0001 KCCS0004C ZCMUOR18 KCCS0036 KCCS0005 KCCS0035 KCCS0006 KCCS0032 KCMZ0015 KCCS0002 KCMZ0013 KCC60067 KCCS0013 KCCS3225 KCCS3223 KCCS3227 HCNJ3824 KCC60068 KAC60003 KCC60058 KCC60050 KCC60051 KCCS0018 HCNJ0601 BCKG0033 KCCS0033 KCC60049 KCCS0001 KCKG0050 KCCJ0002 KCKG0019 KCMU0021 ZCKGB017 KCC60069 KCC60048 Z
Parts – Forks – Leg Assembly – Non-Brake Side REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 15 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 PART # HCBC0408 ZCKG0001 KCCS0004S ZCMUOR18 KCCS0036 KCCS0005 KCCS0035 KCCS0006 KCCS0032 KCMZ0015 KCCS0002 KCMZ0013 KCC60067 KCCS0013 KCCS3225 KCCS3223 KCCS3227 HCNJ3824 KCC60068 KAC60003 KCC60058 KCC60050 KCC60051 KCCS0018 HCNJ0601 BCKG0033 KCCS0033 KCC60049 KCCS0001 KCKG0050 KCCJ0002 KCKG0019 KCMU0021 KCC60057 KCCS0007 KAMU0002 DESCRIPTION 4 X 8 SHCS CLE
Parts – Frame – Mounting Hardware I Frame – Engine, Swingarm, Tank, and Pipe Mounts REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 PART # WCMU0016 HCNL1201 HCBH0880 HCNL0801 MCMUGR02 HCBF0635 HCHA0003 TCHA0004 HCNL0601 TCHA0006 HCBF0685 HCBB0635 HCBF0620 HCNF0602 HCBF0625 MCMUGR03 TCKG0001 HCWF1478 HCBF0616 FCC60020 TAMU0005 FCMU0031 HCWF0803 HCCP0008 TCMU0107 BCMU0027 HCBC0601 FCEX0018 DESCRIPTION SWINGARM BOLT M12 SWINGARM LOCK NUT M8X80mm SOCKET HEAD CAP SCREW M8 LOCK
Parts – Frame – Mounting Hardware II Frame – Seat, Fender, Right Side Panel, Radiator & Shock Mounts REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 PART # FACJ2012 HCBF1040 ECCJ0001 HCBC0608 HCNL0601 MCKGGR00 ECHA0109 HCBC0665 HCBF0616 HCHA0003 HCBH0502 HCWP0002 HCNL0501 HCWF0501 DESCRIPTION FRAME CX50 JR M10X40mm FLANGE HEAD BOLT MOUNTING BRACKET – RADIATOR BOTTOM M6X55mm SOCKET HEAD CAP SCREW M6 LOCK NUT GROMMET – RADIATOR MOUNT (2 REQ’D ON BOTTOM, 2 ON TOP BRACKET) MOUNTING BRACKET – RADIATOR TOP (2 REQ’D) M6
Parts – Front Brakes Front Brakes REF # 1 2 3 4 5 6 7 8 9 10 PART # BAKG0003 BCKG0030 BCKG0023 BCKG0024 BCKG0029 BKKG0001 BCMU0503 HCBC0501 HCBF0640 HCBF0620 DESCRIPTION FRONT BRAKE ASSEMBLY HOSE – BRAKE FRONT ALLOY BRAKE LEVER BRAKE PERCH & MASTER CYLINDER ASSY W/ LEVER CALIPER – FRONT KIT BRAKE PADS, WITH “E” CLIP BRAKE ROTOR M5X12mm SOCKET HEAD CAP SCREW (6 REQ’D) M6X40mm FLANGE HEAD CAP SCREW M6X20mm FLANGE HEAD CAP SCREW ACCESSORY MCMUBF01 BCKG0031 BCKG0028 BCKG0027 BCKG0025 BCKG0026 BCKG0017 BCKG
Parts – Front Wheel Front Wheel REF # 1 2 3 4 5 6 7 8 9 10 11 12 PART # WACJ0001 WCMU0016 HCBC0501 BCMU0503 WCMU0101 WCMU0120 WCCJ0004 WCCJ0003 HCWF1202 HCNL1201 WCMUTU10 WCMU1050D DESCRIPTION WHEEL WITH BEARINGS SPOKE STYLE FRONT AXLE M5X12mm SOCKET HEAD CAP SCREW (6 REQ’D) BRAKE ROTOR – FRONT WHEEL SPACER LEFT (SHORT) BEARING – WHEEL (2 REQ’D) SPACER – WHEEL FRONT WHEEL SPACER RIGHT (LONG) WASHER – AXLE LOCK NUT – AXLE TUBE 10” FRONT TIRE 10” X 2.
Parts – Plastic & Seat Plastic and Seat REF # 1 1 1A 2 2 2A 3&4 3&4 3A 5 5A 5B 5C 5D 5E 5F 5G 6 7 8 9 9A 9B 9C 10 & 11 10 & 11 10A 10B 10C 10D 10E 10F 12 12 12A PART # TCHA0107Y TCHA0107x HCBF0616 TCC60002W TCC60002x HCBF0616 TCCJ0005Y TCCJ0005x TCMU0032 TCHA0001 HCFH0620 TCHA0005 TCHA0006 HCBC0685 HCNL0601 HCBC0645 TCHA0004 TCHA0002 TCHA0003 TCMU0151 TCCM0007 TCCM0007C HCBB0640 MCMU0013 TCCJ0003W TCCJ0003x HCBF0616 HCBF0620 HCNF0602 HCBF0616 HCBF0620 HCNF0602 TCHA0112Y TCHA0112x HCBF0616 DESCRIPTION FRO
Parts – Rear Brake Rear Brake System REF # 1 2 3 4A 4B 4C 5 6 7 8 9 10 11 12 13A 13B 14 15 16 17 18 19 20 21 PART # BAKG0002 BCMU0027 BCMU0501 BCMU0023 BCMU0023T HCBC0501 BCMUSP02 HCBC0601 FCEX0018 BACJ0003 BCKG0006 BCKG0103 HCBF0635 HCBF0620 HCCC0000 HCCC0006 HCPP0832 BCMU0502 HCBC0601 HCBF0620 BCKG0012 BCKG0010 BCKG0013 BCMU0022 DESCRIPTION BRAKE SYSTEM – REAR (M/C-LINE-CALIPER) BRAKE PIVOT BOLT SEAL – BRAKE PEDAL (2 REQ’D) BRAKE PEDAL TOE PIECE M5X 12mm SOCKET HEAD CAP SCREW BRAKE RETURN SPRING M6X16m
Parts – Rear Wheel Rear Wheel REF # 1 2 3 4 5 6 6A 7 7A 7B 8 10 11 12 13 14 15 16 17 18 19 ACCESSORY PART # WAKG2007R WCMU1075D WCMUTU10 PCMU0001 PCMU0100 PCMU0138 PCMU01xx HCBH0702 HCWF0701 HCNL0701 WCMU0016 WCMU0101 WCMU0120 WCMU0034 WCMU0020 BCMU0502 HCBC1616 BCKG0103 BCKG0006 HCWF1202 HCNL1201 DESCRIPTION REAR WHEEL W/BEARINGS TIRE – REAR 10X2.
Parts – Shock Rear Shock REF# 1 2 3 4 5 6 7 8 9 10 10 10 11 PART # SACJ2012 SCMU0043 SCMU0039 SCMU0042 SCMU0058 SCMU0056 SCMU0100 SCMU0040 SCMU0054 SCMUOH05 SCMUOH04 SCMUOH06 HCBF1040 DESCRIPTION SHOCK ABSORBER SHOCK – BEARING SPERICAL SHOCK MOUNT – (2REQ’D) O-RING – SHOCK – BUSHING (4 REQ’D) SHOCK – MOUNT BUSHING (4 REQ’D) SHOCK – WHITE NYLON TIP SET SCREW M6-1.
Parts – Shock - Inside Rear Shock REF# 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 PART # SCMU0037 SCMU0038 SCMU0036 SCC60007 SCMU0051 SCMU0052 SCMU0033 SCMU0050 SCMU0035 HCBB0506 SCMU0044 SCMU0048 SCMU0046 SCMU0034 SCMU0047 SCMU0045 SCC60014 DESCRIPTION O-RING LOW SPEED COMP ADJUSTER O-RING HIGH SPEED COMP ADJUSTER O-RING COMP ADJUSTER CAP O-RING COMPRESSION ADJUSTER O-RING - IFP IFP SEAL BAND O-RING SHOCK BASE RESERVOIR CAP RETAINER RING O-RING CHARGE CAP M5 X 6mm LONG BUTTON HEAD STAINLESS STEEL SEAL HE
Parts – Swingarm Assembly Swingarm REF # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 22 23 24 25A 25B 26 PART # GACJ2011 GCMU0001 GCCJ0001 GCMU0017 HCFH0512 HCWF0501 HCNL0501 HCBF0620 PAKG0001 PCKG0004 HCBFT640 HCNL0601 FAMU0005 FCMU0203 FCMU0202 HCWF0801 HCBH0810 WCMU0016 HCNL1201 WCMU0016 HCWF1202 HCNS1201 HCBF1040 HCCC0000 HCCC0006 HCPP0832 DESCRIPTION SWINGARM SWINGARM BUSHING (SINGLE PIECE) (4 REQ’D) SPACER - PIVOT TUBE (2REQ’D) CHAIN GUARD M5X12mm FLAT HEAD SCREW 5mm FLAT WASHER M5 LOCK NUT
Service Trained technicians with precision gauging and proper assembly fixtures carefully assemble all Cobra engines to specific tolerances. If you feel you have the skills, and the appropriate tools, to perform the following service tasks please follow the instructions closely. The part numbers are listed throughout to help you when ordering parts from your local Cobra dealer. If you do not feel comfortable with the service work log on to: www.cobramotorcycle.
3. Hold the throttle wide open, and kick repeatedly (approximately 20 times) or until the gauge reading does not increase in value with each kick. Base Gasket Selection Tools required 17mm wrench 1mm flexible solder material measurement calipers When rebuilding the ‘top end’ of your Cobra motorcycle, care must be taken to ensure the proper squish clearance. Squish clearance is defined as the minimum distance between cylinder head and piston at TDC.
If top end parts are changed during the course of the maintenance, the squish clearance should be measured, and possibly a different base gasket will be required. The easiest way to measure squish clearance is with 1mm to 1.5mm thick flexible solder wire (available through most popular electronic stores). The process is as follows: Assemble the top end of the engine with either; 1) the crankcase stamp recommended base gasket or, 2) if assembling with a new set of cases assemble with a 0.4mm (0.
Engine Removal To service the bottom end/transmission, the engine must be removed from the frame. Tools required 10, 11, 13, 22 mm wrench 8, 10, 14, 17 & 19 mm sockets 3, 4 & 5 mm Allen wrench 7 mm nut driver, flat or Phillip, screwdriver for hose clamps Spring remover Flywheel / clutch puller (#MCMUTL68) Clutch nut removal tool (#ECMU0078) CFD gear stop (#EAMU0004) Procedure 1. Remove the seat. 2. Turn of the fuel at the petcock and disconnect the fuel line. 3. Remove the tank (8 mm socket). 4.
6. Remove the left hand thread nut holding the CFD to the transmission input shaft using the CFD gear stop (#EAMU0004) and a 19mm socket. 7. Remove the clutch nut / starter gear that holds on the clutch using the clutch nut removal tool (#ECMU0078). 8. With the Cobra flywheel / clutch puller (#MCMUTL68), remove the clutch from the crankshaft (details in Clutch Service portion of this manual). Top End Disassembly Procedure 1. Remove the cylinder head nuts (10mm). 2. Remove the cylinder head outer. 3.
INSPECTION NOTE: Inspect the piston for abrasions and deposits on the top and sides and clean or replace as necessary. INSPECTION NOTE: Piston ring end gap should be between 0.006” (0.16 mm) and 0.020” (0.5 mm) Splitting the Cases 1. Remove the fasteners holding the two halves of the crankcase together. 2. Separate the cases with a proper case splitting tool. CAUTION: Take caution when handling the crankshaft. It is the main power transfer to the rest of the engine.
9. Trim away any excess gasket material if necessary. NOTE: Check engine mount holes for excess material that may cause problems in engine installation. 10. Install the piston with new wrist pin bearing and, pin and clips. CAUTION: Be sure to install 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 bearing. 11. Install the piston rings. CAUTION: Ring end gap should be no less than 0.006” (0.
Ignition portion of this manual. 22. Install the water pump outlet pipe (apply Hi-Temp RTV silicon gasket maker to the threads before assembly) before installing the clutch and rotate to a vertical position with the engine resting on bench 23. Install the CFD. 24. Install the clutch per Clutch Installation section in this manual. 25. Install the coolant drain plug with copper washer (11 ft-lb, 15 Nm). 26. Make sure that the exhaust spacer is on the cylinder (53 in-lb, 6 Nm). 27.
Figure 30 Figure 31 Clutch puller installation CAUTION: Do not use a jaw type puller or use the 6mm tapped holes as jackscrews or you are likely damage the clutch or drum. CAUTION: It is possible to cause damage to the piston when using the piston stop. Care must be used when removing and installing the clutch arbor and using the piston stop. 4. If necessary apply heat to the center clutch hub. CAUTION: Do not heat the crankshaft threads or the aluminum shoes. 5.
CLUTCH ASSEMBLY REFERENCE DRAWING REF # PART # DESCRIPTION 1 CAMU0013 Set of three shoes, springs, bolts, flat washers & nuts 2 CAMU0010 Set Of three springs, washers, bolts & nuts Not Shown CAMU0006 Complete assembled clutch (Arbor, shoes and washer stacks) Figure 32 Some configuration of clutch spring stack. Each ‘spring’ stack contains multiple springs (Belleville washers) - arranged into three, four, or five ‘flying saucers’, or turned away against the flat washer(s). Shown is the 4 ½ stack..
Use the table above to order adjustment washers. Replace the stock washer with the proper combination of adjustment washers that delivers the desired clutch hit. CAUTION: It is easy to prematurely damage the clutch and other engine components with improper clutch adjustment. If you are unsure of how to adjust the clutch, contact the Cobra Technical Support Group before making adjustments. Clutch shoe wear: This can be measured by the overall diameter of the shoes installed on the arbor.
2. Clean the threads of the stack bolt and the clutch with brake cleaner removing all old thread locking material. 3. Assemble the stacks and shoes on the arbor using high strength thread lock material to the stack bolt and tighten to 12 ft-lb (16 N-m). CAUTION: Avoid allowing excess thread lock material to contact the spring washers and the clutch or the clutch is likely to malfunction. 4. Clean the threads of the crank shaft and the clutch nut. 5. Install the clutch arbor on the crank.
CAUTION: Because of the amount of heat generated by the clutch and engine during extended periods of riding, it is advisable to remove the ignition cover afterward to allow the ignition to cool off. The heat transfers through the cases and can damage the stator as it cools off because of lack of airflow around the stator. Ignition will overheat if the gap between the rotor and stator is not large enough. There should be even clearance as the rotor rotates relative to the stator.
6. Set the dial indicator to zero 7. Turn the crankshaft clockwise until the dial indicator reaches 0.040” (1.0mm) from top dead center. 8. At this position the line on the rotor should align with the center of the stator coil at 5 o’clock position on stator frame. If not loosen the three 5mm bolts to adjust the stator. 0.040” before TDC Figure 39, Lining up the line on the rotor with the line on the stator. Figure 40, Using a dial indicator to measure piston height for setting ignition timing.
Tools recommended for impeller service: Flat head screwdriver 13mm- hex wrench 3mm hex key 4mm hex key 5mm hex key 8mm hex key Water Pump Installation tool MCMUTL09, 2010 and newer JR & King MCMUTL08, 2009 and older JR models Slide hammer with fitting to thread into threads on end of shaft (M5x1.0) single and double hook ends for removing plastic impeller Dead blow hammer COBRA IMPELLER SERVICE INSTRUCTIONS 1. Remove radiator cap and drain engine coolant as described above.
9. Prepare for assembly by installing the water pump assembly into the assembly tool and align the tool with engine case making sure alignment pin is in proper hole. CAUTION: Damage may occur if one attempts to install the water pump and the device is not orientated correctly. If the tool does not sit flat against the cases, the orientation of the tool to the engine is not correct.
13. Reinstall the pulley, belt and fan cover using a 3mm hex key to stop the rotation of the water pump assembly while tightening with medium strength thread lock to 10 ft-lb (14Nm). 14. Reinstall the cover NOTE: Refill the coolant system with 50/50 antifreeze-coolant / distilled water. CAUTION: Do not mix Propylene Glycol based coolant / antifreeze solutions with Ethylene Glycol based coolant / antifreeze solutions.
Indications that the engine is running too lean are: Engine cutting out on top end. Engine overheating and ultimately seizure. White spark plug CAUTION: It is much safer to operate the engine slightly rich as opposed to slightly lean. This is because an overly rich engine will just run poorly while an overly lean engine will seize, potentially causing an expensive top end rebuild and a DNF. To richen the carburetor: 1. Change the main jet one number at a time (larger). 2.
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. Anything abnormal, replace the reeds. Take the reed cage out and hold it up to the light and look in through the cage. If you see light between the reed pedals and the frame, then replace the reeds. If you do not see light, then the reeds should be ok.
Rear wheel pullers Disassembly: 1. Remove axle, and back wheel assembly. 2. Pull the rear wheel pullers out of the back of the swing arm. Figure 47 Rear wheel alignment: Either Accurately measure the distance from the swingarm pivot to the axle center on each side or From the rear of the bike, sight up through both sprockets to ensure that the chain is running in a straight line (no bend in between or jog at either sprocket).
Front Forks Tools recommended for front fork service: Flat head screwdriver Hammer Pick Seal driver MCMUTL02 9/16” (loose 14 mm) wrench 25mm wrench or socket 2.5 wt fork oil FORK DISASSEMBLY PROCEDURES: o o o o o o o o o Using the 25mm wrench, remove the fork cap. Drain the fork oil into a suitable container. Disconnect the fork cap from the damper rod (9/16” wrench & 25mm wrench).
CAUTION: It is helpful to cover the sharp corners of the fork leg with tape or thin plastic before sliding on the new seal. Also take care that the inner lip is not folded over when installing. 4. Slide bushing (#3) onto lower fork leg. 5. Install the glide ring into groove on lower fork leg. 6. Slide the bushing over the glide ring about 1/4" to hold the glide ring in the groove. 7. Insert the lower leg assembly into the upper fork tube about 5-6". 8.
Tuning Clutch There are performance characteristics to observe and things to measure.
1. Clutch spring stack to tall Wrong configuration Too thick a flat shim in the stack 2. Spring rate too high (wrong configuration with proper stack height) 3. Clutch arbor shoulder bolt is too short 4. Clutch shoe material has worn too thin 5.
Effective length of the shoulder on the clutch arbor bolt (see Figure C1). Nominal is 16.00mm (0.630”). As this decreases, the spring stack needs to decrease equally. This can change due to the shoulder bolt ‘setting’ into the arbor (see C2) Figure C1 Figure C2 If your effective shoulder length is off, or your shoes are worn, adjust the height of your overall combined spring stack accordingly (i.e. if your effective shoulder length is 0.5mm short of the 16.
Gearing For a bike with a centrifugal clutch, it’s better to be geared too low than too high.
Suspension Adjustment 1. Front forks 1.1. Fork oil 1.1.1. Oil type 1.1.1.1. Heavier weight oil – more damping – slower responding 1.1.1.2. Lighter weight oil – less damping – quicker responding 1.1.2. Oil quantity / level 1.1.2.1. Greater quantity / higher level – greater bottoming resistance, stiffer near the end of the travel. 1.1.2.2. Smaller quantity / lower level – less bottoming resistance, less stiff near the end of the travel. 1.2. Fork spring 1.2.1.
Front Fork Operation The front suspension on the CX50SR works under the principals of hydraulic damping, and it features full adjustability to help tune the fork to meet each rider’s needs. The CARD fork contains MXT ‘Smart Leg’ technology that provides very progressive operation; allowing a small bike to perform well on track surfaces ripped up by larger machines. The key to Smart Leg technology is to understand that each leg has a different role. The brake side leg features a conventional open cartridge.
it counter-clockwise will decrease it. This is illustrated by the “HARD” and “SOFT” in the figure at the right. The Smart Leg cap is labeled “Speed Sensitive Bottoming Control”, and this adjuster provides a range of control over how progressive the fork feels. Turning the screw clockwise increases the fork’s resistance to bottoming, while turning the screw counter-clockwise decreases it.
Once you have the suspension adjusted for decent overall feel, you can make proactive adjustments when faced with different racing conditions. Situation Sand track Sand track Long fast track Tight slow track Mud track Actions Lower the rear end (increase race sag). Stiffer compression and rebound damping. Lower the forks in the clamps by 3 mm. Raise the forks in the clamps by 3 mm. Lower the bike if the rider has difficulties touching the ground.
CAUTION: Proper jetting is very important for engine performance and engine life. Symptoms of improper jetting are listed below.
NOTE: Perform all jetting changes on a motorcycle that has been warmed up to proper operating temperature. The carburetor on your Cobra motorcycle is quite adjustable. Figure 59 shows its range of adjustment and in particular what adjustable component affects what range of operation (specifically throttle position). Figure 59 FUEL SCREW ADJUSTMENT: Adjust for maximum idle speed The fuel adjustment screw is located on the left side of the carburetor.
Troubleshooting 1) Engine not behaving properly a) Carburetor top is installed backwards (happens a lot) b) The carburetor slide indexing pin is missing c) Wrong spark plug installed (8339 Champion to be used on ’04 or later & no mods) d) Needle clip is on top of plastic not below e) Air leak – find where with carb cleaner or similar f) Ground wire or ignition leads have fault 2) Engine is down on power a) Clutch engagement is not set properly b) Jetting is incorrect c) Silencer needs repacked d) Exhaust
i) Spark plug fouled ii) Wrong spark plug installed (8339 Champion to be used on ’04 or later & no mods) iii) Spark plug cap off iv) Engine Shut-off ‘kill’ switch is shorted v) Bad electrical ground vi) Stator winding damaged d) Exhaust is plugged 6) Overheating a) Bad stator b) Water pump pulleys or belt broken c) Water pump impeller broken or bolt out d) Jetting too lean e) Too much throttle blipping f) Too high gearing g) Kinked radiator hose h) Rear brake dragging i) Chain too tight j) Air leak 7)
Index Air Filter Maintenance ................... 14 Frame Parts .................................. 31 Airbox Frictional Drive .............................. 16 Parts .......................................... 18 Front Brake Bars and Controls ......................... 19 Parts .......................................... 33 Base Gasket Selection.................. 42 Front Wheel Parts ......................... 34 Break-In .......................................... 6 Fuel System Carburetor Service..
Engine ....................................... 23 Parts .................................... 38, 39 Exhaust ..................................... 27 Slip Clutch ..................................... 16 Forks ......................................... 28 Spark Plug Frame ........................................ 31 Recommended ............................ 4 Front Brake ............................... 33 Specifications .................................. 4 Front Wheel ...............................
