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2004 CM50 

 

Owners / Service / Parts 

 
  

 

 

 

 
 
 

“CHAMPIONS START HERE” 

 

 

Summary of Contents for 2004 cm50

Page 1: ...2004 CM50 Owners Service Parts CHAMPIONS START HERE...

Page 2: ...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 Motorcy...

Page 3: ...NTENDED 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 MOTORCYC...

Page 4: ...nt 17 Parts 18 Parts Airbox and Inlet System 18 Parts Carburetor 20 Parts Coolant System 21 Parts Electrical System 22 Parts Engine Bottom End and Transmission 23 Parts Engine Clutch and Kick Starter...

Page 5: ...ingarm Assembly 39 Service 40 Engine Service 40 Engine Removal 41 Complete Engine Disassembly Procedure 42 Top End Disassembly Procedure 42 Splitting the Cases 43 Engine assembly 44 Clutch 49 Ignition...

Page 6: ...ter 8904 1 colder Gap 0 023 0 025 0 58 0 64 mm Ignition timing 0 050 1 3 mm Before To Dead Center BTDC Fuel type High octane pump gasoline RACE FUELS ARE NOT RECOMMENDED Oil type Cobra Venom 2 cycle R...

Page 7: ...Rear tire 2 75 10 Pressure 15 psi min 20 psi for hard pack or rocky conditions Front fork Marzocchi 32mm Fork oil type SAE 20 weight Fork oil amount 200 ml 6 8 oz oil change 220 ml 7 4 oz rebuild Coll...

Page 8: ...gnition rotor nut 40 480 54 10 x 1 25 mm Rear Sprocket Bolts 18 216 24 7 mm Rear shock mounts 40 480 54 10 x 1 5 Rear Axle Bolt 25 300 34 12 mm Use green wicking bearing retainer thread locker with pr...

Page 9: ...ck Spring Less than 38 light KCMZ0012A SCMUOH04 275 lb in 38 45 std KCMZ0012 SCMUOH05 285 lb in 46 to 55 stiff KCMZ0012B SCMU0H06 295 lb in Suspension Valving Damping Rate Fork Valving Compression rig...

Page 10: ...irst hour of operation o Follow the starting procedure listed in this manual o Avoid prolonged operation at Wide Open Throttle After 1 hour of operation o Check for loose bolts and nuts on the bike an...

Page 11: ...a Motorcycle use only the recommended fuels Testing has shown that most race fuels actually degrade performance When your pre ride inspection is complete the bike may be started For a cold engine foll...

Page 12: ...they are riding 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 When washing the bike be care...

Page 13: ...r cracks in the paint that might indicate that the metal has been stressed beyond it s safe limits Replace or get properly rewelded as necessary o Inspect the rear sprocket damper plate for bending or...

Page 14: ...g If it does not loosen up remove the kick starter cover and kicking assembly Grease the shaft M1 Replacing Transmission Clutch Lubricant Tools needed 225 ml 7 6 oz Cobra Venom 3 Shoe Clutch Milk Part...

Page 15: ...is in place 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 s...

Page 16: ...e hub 2 Adjust the brake cable to desirable position 3 Tighten the 10mm nut CAUTION If you tighten the front brake up too much the brakes may hang up causing the brake pads to wear incorrectly and pre...

Page 17: ...emove the filter oil 5 Clean the filter in hot soapy water to remove all dirt particles 6 Allow it to dry thoroughly 7 Saturate with filter oil and remove excess 8 Reinstall the filter boot assembly t...

Page 18: ...axle bolt goes through 6 Depress the white plastic cap inwards down and remove the wire spring clip from its groove 7 Remove the white cap the fork spring preload sleeve and the fork spring NOTE Depre...

Page 19: ...T MANIFOLD 5 HCWF0601 6MM FLAT WASHER 6 HCBC0625 M6X25 SOCKET HEAD CAP SCREW 7 MCKGHO01 HOSE CLAMP CARBURETOR TO MANIFOLD 8 RACM0002 CARBURETOR 14MM 9 FCMU0067 THROTTLE CABLE 10 RCCM1301 VELOCITY STAC...

Page 20: ...3 TCMU0008 GRIPS SET OF TWO 4 FCMU0067 THROTTLE CABLE 5 FCMU0033 KILL SWITCH ASSEMBLY 6 KCMZ0001 M8X50 SOCKET HEAD CAP SCREW 4 REQ D 7 KCMZ0003 LOWER HANDLE BAR CLAMP 2 REQ D 8 KCMZ0002 TOP HANDLE BA...

Page 21: ...TER 11 RCMU0006 TOP CARB SCREW 12 RCMU0106 CARB TOP 13 ZCMU0007 TOP CARB GASKET 14 RCMU0004 SLIDE SPRING 15 RCMU0205 NEEDLE RETAINER PLATE 16 RCMU0007 NEEDLE CLIP 17 RCMU0204 CHOKE ASS Y 2001 CM 20 RC...

Page 22: ...ATOR HOSE LEFT 3 MCMUCL02 HOSE CLAMP 4 ECHA003 MOUNTING BRACKET RADIATOR BOTTOM 5 HCBC0607 M6X50 SOCKET HEAD CAP SCREW 6 HCNL0601 6MM LOCK NUT 7 MCKGGR00 GROMMET RADIATOR MOUNTING 8 MCMUHO03 RADIATOR...

Page 23: ...R PLUG 8904 1 3 FCMU0033 KILL SWITCH ASSEMBLY 4 HCBC0516 SCREW M5 X 16 2 PER 5 HCNL0601 6MM LOCK NUT 6 ECMU1210 BRACKET COIL MOUNT 31 HCWP0001 WASHER FOR STATOR 3 PER 32 HCBC8312 SOCKET HEAD CS 8 32X1...

Page 24: ...RING TRANMISSION SECONDAY SHAFT 9 ECMU0038 CRANKSHAFT 10 ECKGBR01 BEARING TRANSMISSION OUTPUT SHAFT 13 HCDP1401 DOWEL ENGINE CASE ALIGNEMENT 14 HCBH0805 M8X12 SCREW 15 HCWC0000 COPPER GASKET 16 ECMU01...

Page 25: ...SPRING KICK LEVER 16 CCMU0031 CLUTCH ARBOR 17 CAKG0005 CLUTCH SHOE SET OF 3 NOT SHOWN CAKG0004 SET OF 3 CLUTCH SHOES WITH SPRINGS WASHER BOLT NOT SHOWN CAKG0002 CLUTCH ASSY W ARBOR SHOES SPRINGS WSHR...

Page 26: ...2 ECKG0073 IMPELLER WATER PUMP 13 HCBB0001 IMPELLER SCREW SHCS 10 32X1 2 14 HCSS8201 RETAINING SCREW SHCS 8 32X3 8 15 HCBC0603 CASE SCREW SHCS M6X30 16 HCBC0606 CASE SCREW SHCS M6X45 3 REQD 17 HCBC060...

Page 27: ...WRIST PIN 9 ZCMUOR07 O RING EXHAUST FLANGE 10 ECKG0015 EXHAUST FLANGE 11 HCBC0602 M6X20 EXHAUST FLANGE SCREW 2 REQ D 12 HCNS1401 NUT CYLINDER HEAD 1 4 20 4 REQ D 13 HCWF1401 FLAT WASHER 1 4 4 REQ D 1...

Page 28: ...05 EXHAUST SPRING SHORT 4 MCMUGR06 PIPE GROMMET MALE 5 MCMUGR07 PIPE GROMMET FEMALE 6 MCMUSP02 PIPE GROMMET SPACER 7 HCWF1478 PIPE GROMMET WASHER 8 HCBF0635 M6X35 FLANGE HEAD BOLT 10 XCKG0009 PIPE SIL...

Page 29: ...HCCC0002 CLAMP BRAKE CABLE 6 HCBC0520 M5X20 SOCKET HEAD CAP SCREW 7 HCNL0501 5MM LOCK NUT 8 HCBF0616 FENDER BOLT M6X16 FLANGE HEAD 4 REQD 9 KCMZ0025 TRIPLE CLAMP LOWER WITH STEM 10 HCBC0625 M6X25 SOC...

Page 30: ...KCMZ0015 FORK SEAL 16 KCMZ0016 WASHER 17 KCMZ0017 SEALING RING FOR REBOUND PISTON 18 KCMZ0118 PISTON ROD REBOUND 18A KCMZ0118A PISTON ROD COMPRESSION 19 KCMZ0019 REBOUND SPRING 20 KCMZ0020 FORK LEG O...

Page 31: ...T HEAD CAP SCREW 4 HCNL0801 8MM LOCKNUT 5 MCMUGR06 PIPE GROMMET MALE 6 MCMUGR07 PIPE GROMMET FEMALE 7 MCMUSP02 PIPE GROMMET SPACER 8 HCBF0630 PIPE GROMMET WASHER 9 HCHA0003 6MM CLIPNUT 10 BCMU0008 CAB...

Page 32: ...CRIPTION FAMU0004 FRAME 2004 CM50 1 HCBB0630 M6X30 BUTTON HEAD CAP SCREW 2 HCHA0003 6MM CLIPNUT 3 HCBF0620 M6X20 FLANGE HEAD BOLT 4 HCNF0602 6MM NYLOC FLANGE NUT 5 HCBF0630 M6X30 FLANGE HEAD BOLT 6 MC...

Page 33: ...L0601 6MM LOCK NUT 4 MCKGGR00 GROMMET RADIATOR MOUNT 2 REQ D ON BOTTOM 1 ON TOP BRAC KET 5 ECHA0109 MOUNTING BRACKET RADIATOR TOP 6 HCBC0660 M6X60 SOCKET HEAD CAP SCREW 7 FCMU0057 CHAIN ROLLER 8 HCWF1...

Page 34: ...AKE ARM FRONT 3 BCMU0005 CABLE CLAMP WASHER NUT 4 BCMU0006 CABLE ADJUSTOR 5 BCMU0110 BRAKE SHOE PAIR 6 BCMU0010 SPRING BRAKE RETURN 7 BCMU0011 PUSH NUT BRAKE SPRING 2 REQ D 8 BCMU0007 BRAKE STOP 9 HCB...

Page 35: ...WAMU0300 FRONT WHEEL COMPLETE 2 WCMU0250 FRONT TIRE 10X2 50 3 WCMUTU10 TUBE 10 4 WCMU0014 FRONT AXLE 5 HCWF1202 WASHER AXLE 6 WCMU0023 FRONT WHEEL SPACER 7 WCMU0020 BEARING WHEEL 2 REQ D 8 WCMU0004 S...

Page 36: ...TCHA0006 SPACER FRONT TANK MOUNT 2 REQ D NOT SHOWN HCBC0685 M6X85 SHCS FRONT TANK MOUNT NOT SHOWN HCNL0601 6MM LOCK NUT FRONT TANK MOUNT BOLT NOT SHOWN HCBC0645 M6X45 SOCKET HEAD CAP SCREW NOT SHOWN T...

Page 37: ...HCNL0801 8MM LOCK NUT 6 HCBH0602 M6X25 HEX HEAD BOLT BRAKE STOP ADJUST 7 HCNS0601 6MM NUT 8 BCCM0105 BRAKE ROD 9 BCMU0111 BRAKE ROD BARREL 10 HCNW0001 BRAKEROD WINGNUT 11 BCMU0109 BRAKE HUB REAR 12 B...

Page 38: ...U0016 REAR AXLE 7 HCPA0002 AXLE HEAD FIXING PLATE 8 WCMU0001 REAR WHEEL SPACER SPROCKET SIDE 9 WCMU0020 WHEEL BEARING 2 REQ D 10 WCMU0003 WHEEL BEARING SPACER REAR 11 BCMU0109 BRAKE HUB REAR 12 WCMU00...

Page 39: ...Parts Shock Figure 27 REAR SHOCK REF PART DESCRIPTION 1 SACM2004 SHOCK ABSORBER 2 SCMUOH05 SPRING STANDARD 285 lb in SCMUOH04 SPRING LIGHT 275 lb in SCMUOH06 SPRING HEAVY 295 lb in 3 HCBC1001 M10X45 S...

Page 40: ...MM FLAT WASHER 7 HCNL0501 5MM LOCK NUT 8 HCBF0620 M6X20 FLANGE HEAD BOLT 9 PCKG0000 CHAIN GUIDE FRONT BACK 11 PCKG0004 CHAIN GUIDE BOTTOM SLIDER 12 HCBF1401 X 20 X 1 FLAT HEAD SCREW 2 REQ D 13 HCNL140...

Page 41: ...fee Call 330 549 9603 for details Engine Service One method for determining whether the top end of your engine needs rebuilt is to perform a WOT Wide Open Throttle kicking compression test Before per...

Page 42: ...removed from the frame Tools required 5 16 10 14 mm socket 10 13 22 mm wrench 10 17 19 mm sockets 9 64 3 4 5 mm hex key Allen wrench 7 mm nut driver flat or Phillip screwdriver for hose clamps Spring...

Page 43: ...Engine Disassembly Procedure 1 Remove the magneto cover 9 64 hex key 2 Remove the bolt from the water pump shaft 4mm and slide off the belt cover and the water pump belt 3 Using a flywheel holding to...

Page 44: ...deposits are all are found a Clean with muratic acid b Once the deposits are removed inspect for abrasions and missing surface coating i If there are abrasions or missing coating replace ii If all lo...

Page 45: ...laced every racing season Engine assembly CAUTION For any seals that are to be installed apply a light amount of grease to the seals ID and a small amount of Loctite to the OD 1 Press the three bearin...

Page 46: ...45 Figure 29 Figure 30...

Page 47: ...to the left crank case half being sure to install the gasket behind the connecting rod 12 Assemble the two case halves together with the shim installed between the crank throws Be sure to remove the...

Page 48: ...gasket material to the cylinder deck areas around the coolant passage and cylinder studs as shown in figure 29 Figure 33 18 Install the base gasket 19 Install the cylinder being sure that the piston r...

Page 49: ...before assembly before installing the clutch and rotate to a vertical position with the engine resting on a bench 27 Install the clutch per Clutch Installation section in this manual 28 Install the co...

Page 50: ...over on 3 Remove the clutch nut not left hand thread on the end of the crankshaft with the clutch nut removal tool 4 Attach the COBRA CLUTCH PULLER There are three 6mm clutch puller holes located on t...

Page 51: ...are being installed then it is important to reinstall per figure 34 CLUTCH ASSEMBLY REFERENCE DRAWING REF PART DESCRIPTION 1 CAKG0004 Set of three shoes springs bolts flat washers nuts 2 CAMU0008 Set...

Page 52: ...is also makes your engine tend to run hotter which decreases engine power and degrades ignition stator efficiency It is important to train your rider NOT to be a throttle blipper CAUTION Sludge build...

Page 53: ...crankshaft 5 Apply a small amount of wicking bearing retainer green thread lock agent to the center tapered section of the crankshaft and taper of clutch arbor CAUTION Lean the bike engine such that a...

Page 54: ...and tightening in the order specified in figure 36 5mm hex key 5 8 ft lb 7 8 Nm CAUTION Prior to tightening the six clutch cover bolts press the kick lever down to ensure proper kick gear alignment F...

Page 55: ...engine is hot it is EXTREMLY important to take the ignition cover off put a fan on it to let it cool and spray it with CRC 3 36 or WD 40 Proper stator care is important for the durability of the ignit...

Page 56: ...es on the rotor and stator then press the rotor onto the crankshaft firmly figure 37 3 Torque the nut on the rotor to 40 ft lb 54 Nm 4 Recheck the timing following the procedure of timing your ignitio...

Page 57: ...sion and abnormal smell Fill the radiator up to the bottom of the radiator filler neck with coolant Install the cap turning it clockwise about turn Tools recommended for impeller service Flat head scr...

Page 58: ...etainer screw using a 3 32 hex key Figure 41 item 2 Figure 45 12 Heat engine case around area of impeller lightly with a small Burnsmatic propane torch Using a 3 8 diameter x 8 long steel rod tap impe...

Page 59: ...gure 44 Figure 48 16 Re assemble in same order of disassembly CAUTION Clean all threads and use green wicking bearing retainer thread locker on the belt retainer screw NOTE Apply Ultra black Hi Temp R...

Page 60: ...102 RUBBER CABLE CAP SEAL 9 RCMU0003 CABLE ADJUSTER 11 RCMU0006 TOP CARB SCREW 12 RCMU0106 CARB TOP 13 ZCMU0007 TOP CARB GASKET 14 RCMU0004 SLIDE SPRING 15 RCMU0205 NEEDLE RETAINER PLATE 16 RCMU0007 N...

Page 61: ...on the top end it should be leaned out Leaning it out can be done by 1 Changing the main jet to a smaller number 2 Raising the needle clip this lowers the jet needle one notch at a time on the slide...

Page 62: ...tor 4 Disassemble the carburetor CAUTION Do not use compressed air on an assembled carburetor Or the pressure may deform the float Do not use a strong carburetor cleaning solution which could attack t...

Page 63: ...Figure 51 The presence of light indicates that the reeds should be replaced or possibly turned over Exhaust The pipe is a crucial element to a motorcycle Any kinks dents or damage done to the pipe wi...

Page 64: ...ockets are also available Watch for bending and warping of the outside rear damper plate If it is bent or warped the rubber dampers in the sprockets do not last as long as when using a straight unit U...

Page 65: ...y 2 Pull the rear wheel pullers out of the back of the swing arm Rear wheel alignment By eye ensure that the rear sprocket is running true in line planar with the front sprocket When the sprockets are...

Page 66: ...performed in the left fork leg This allows easy adjustment of the damping characteristics by appropriately changing the viscosity of the fork oil in the fork leg controlling the camping characteristi...

Page 67: ...in it e Compression is low i Piston ii Rings f Reeds are damaged g Ignition timing is incorrect 3 Engine is excessively loud a Silencer needs repacking 4 Engine blubbers at high RPMs a Jetting too ric...

Page 68: ...63 Electrical Parts 22 Engine Parts List 19 Specifications 5 Exhaust 62 Parts 27 Fork Oil Replacement 17 Forks Adjustment 65 Parts 28 Frame Parts 30 Front Brake Adjustment 15 Parts 33 Front Wheel Part...

Page 69: ...garm 39 Top End 26 Triple Clamps 28 Parts List Engine 19 Plastic Seat Parts 35 Pullers 64 Rear Brake Adjustment 15 Parts 36 Rear Wheel Damper 63 Parts 37 Pullers 64 Reeds 62 Shock Parts 38 Spark Plug...

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