Cobra King 2003 manuale d’uso

2003 KING Owners / Service Manual “CHAMPIONS START HER E”[...]

1 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. 11511 Springfield Road North Lima, Ohio 44452 MCKG2003.3[...]

2 DISCLAIMER OF WARRANTY This motorc ycle 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 KING IS A COMPETITION MODEL ONLY AND IS NOT MANUFACTURED FOR, NO R SHOULD IT BE USED ON PU[...]

3 Table Of Contents General Information ......................................................................................................... 4 Specifications - General .............................................................................................. 4 Optional Components ............................................................[...]

4 General Information Specifications - General Items KING Dimensions Wheelbase 39” (991mm) Wheel size 10” (254mm) rear, 12” (305mm) front Seat height 26” (660mm) Engine Type 2 - stroke, single cyl inder, reed valve Cooling system Liquid - cooled Displacement 49.8 cc Bore and stroke 39 mm x 41.7 mm Ignition system Electronic Spark plug Split[...]

5 Chassis Front tire 2.50 - 12 Pressure 15 psi minimum Rear tire 2.75 - 10 Pressure 15 psi min. (20 psi for hard pack or rocky conditions) Front fork Cobra 30mm USD Fork oil type SAE 5 weight Fork oil amount 118 ml (4.0 oz) Optional Components • Carburetor jets • Sprockets o Front o Rear • Suspension Springs Weight of Rider (lb) Fork Spring S[...]

6 Specifications - Torque Values Torque Value Fastener ft - lb in - lb Nm Size & Remarks Cylinder head nuts 9.2 110 12 ¼” Crankcase bolts 6.6 80 9 6 x 1.0 Spark plug (SP) (SP) (SP) 14 x 1.25 Stator bolts 2.1 25 2.8 #8 Stator cover bolts 1.7 20 2.3 #8 Clutch cover bolts 5.8 70 7.9 6 mm Clutch 40 480 54 10*** Front axle nu t 25 300 34 12 x 1.2[...]

7 Break - In Procedure Your Cobra KING is a close - tolerance high performance machine and break - in time is very i mportant for maximum life and performance. The KING 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 -[...]

8 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 do not have improper wear. • Inspect the frame, for; o Cracks in the metal. o Cracki[...]

9 General Tips 1. Always wear a helmet and other protective riding gear. 2. 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. 3. Make sure your riders’ foot is not resting on the foot brak e while they are riding . 4. Evaluate the bikes jettin[...]

10 CAUTION: 1. Because of the amount of heat generated by the clutch and engine during extended periods of riding, it is a dvisable 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. 2. If you ever need[...]

11 2. Lean bike against something or set on stand with oil drain hole. 3. Using a 13 mm wrench, remove the oil drain bolt located on the right side of the engine, on the clutch cover, near the brake lever (Item 2, figure 1). Figure 1 NOTE: You may need to adjust the brake pedal (up or dow n) to gain access to the drain bolt. 4. After it has drained[...]

12 M2: Chain adjustment Figure 2 1. Make sure that the rear wheel is aligned properly. 2. Push down on the sea t, compressing the suspen - sion down to where the chain is tightest. 3. The chain should not be too tight but not too loose. A minimum of 2.5 in. of slack should be between the swing arm and the chain. M3: Rear brake adjustment Tools reco[...]

13 M4: Air Filter Cleaning Tools recommended for air filter maintenance: • Flat head screwdriver • Air filter oil • 5mm hex key • Foam filter oil The Cobra is equipped with a special designed sock filter. It is very importan t to keep it clean and properly oiled with high quality water - resistant foam filter oil. It’s very important to o[...]

14 e. Work the damper rod up and down several times. f. Allow to drain completely. Assembly procedure 1. Fill the fork leg with 4 oz (118 ml) 5 wt fork oil. 2. Measure the fork oil level to the top of the fork tube with the leg collapsed, and reco rd for tuning purposes. 3. Install the fork spring. 4. Reconnect the damper rod to the fork cap (12 ft[...]

15 Engine Service / Parts REF. # PART # DESCRIPTION REF. # PART # DESCRIPTION 1 CAKG0002 Clutch, Complete 44 ZCKG0002 Gasket, Base 2 CAKG0004 Shoes, Clutch w/ Washer Springs 45 ECKG0041 Cylinder, 50cc 3 CAMU0008 Spring Set, Washer type for Clutch 46 ZCMUOR07 Oring, Exhaust Flange 4 CCMU0031 Arbor for 3 Shoe Clutch 47 ECKG0015 Exhaust Flange 5 ECMU0[...]

16 Figure 5[...]

17 Trained technicians with precision gauging and proper assembly fixtures carefully assemble all Cobra engines to specific clearances. 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[...]

18 Engine is Fresh Measured Value Engine Down on Power Measured Value * 0.9 Engine NEEDS Rebuilt Measured Value * 0.8 Example 110 psi 11 0 psi * 0.9 = 99 psi 110 psi * 0.8 = 88 psi Your Values Procedure for Compression Testing 1. Shut off the fuel petcock. 2. Install the compression gauge into the spark plug hole. 3. Hold the throttle to wide open,[...]

19 NOTE: Only drive the swingarm bolt far enough to clear the engine, leave it holding the one side of the swingarm to the frame 13. Remove the engine from the right side of the frame. 14. Locate a suitable container for the engine coolant and remove radiator hoses from engine (coolant will drain). NOTE: If the coolant looks to be free of contamina[...]

20 4. Remove the cylinder. Muratic acid can be dangerous. Follow the manufacturers instruct ions closely. 5. Remove the piston clip with a scribe. 6. Remove the piston pin with a piston pin remover. INSPECTION NOTE: Inspect the piston for abrasions and deposits on the top and sides and clean or replace as necessary. E4: Splitting the Cases 1. Remov[...]

21 CAUTION: Take caution when handling the crankshaft. It is the main power transfer to the rest of the engine. If it is out of alignme nt, it will cause premature failure of your bearings which can lead to serious damage to the cylinder and the rest of the engine. Do not try to true the crank yourself. Truing the crank should be done professionall[...]

22 Figure 6 Figure 7[...]

23 10. Insert dowel pins in the left side case as shown in figure 8. Figure 8 11. Apply gasket sealer (NAPA Aviation Form - A - Gasket #765 - 1210 or equivalent) to the mating surfaces of both crankcase halves. 12. Apply the crankcase gasket to the left crank case half being sure to install the gasket behind the connecting rod. 13. Insert the screw[...]

24 CAUTION: Be sure to align the piston such that the arrow on the top piston surface points to the exhaust (front of bike/engine). 17. Apply gasket sealer (NAPA Aviation Form - A - Gasket #765 - 1210 or equal) to the c ylinder deck areas around the coolant passage and cylinder studs as shown in figure 10. Figure 10 18. Install the base gasket 19. [...]

25 22. Install O’rings as shown in figure 12. Figure 12 23. Install the cylinder head and torqu e to 9.2 ft - lb (12 Nm) 24. Install stator reinstalling the grommet and wires (snug the bolts). 25. Install the rotor per Rotor Installation section, under the ES4: Ignition portion of this manual. 26. Install the water pump outlet pipe (apply Ultra b[...]

26 ES3: Clutch Cobra clutch puller assembly: Figure 13 Clutch puller diagram Figure 14 Tools recommended for clutch service: • 22mm socket • Universal clutch puller - a universal puller that pulls the clutch, main drive gear and rotor. (Part # MCMUTL70). • 5mm T - handle • Clutch nut removal tool (Call local dealer for details) • Cobra 3 [...]

27 CLUTCH WASHER STACKUPS: Once the clutch is removed, and cool to touch, carefully put it into a vice and remove the center shoulder bolt out of each clutch shoe. You will probably have to heat t he center hub again to remove the bolts. Once you get a bolt loosened, carefully remove it with the shoe and observe the way the spring washers are stack[...]

28 CAUTION: Sludge build - up between the spring washers also keeps the clutch shoe from engaging fully and this will cause the clutch to start to s lip. So you will need to clean the sludge out or just replace the spring washers and bolts with new ones. How quickly this sludge builds up depends on how often you change your oil and whether your rid[...]

29 CAUTION: It is also important that all three shoes are stacked the same. (See figure 15) 2. Clean the threads of the stack bolt and the clutch with contact cleaner removing all old thread locking material. 3. Apply high strength (red) thread lock material to the stack bol t and tighten as tight as possible without stripping the Allen head. CAUTI[...]

30 8. Install the clutch cover taking care to put the two longer bolts in their proper locations and tig htening in the order specified in figure 17. (5mm hex key, 5.8 ft - lb, 7.8 Nm). Figure 17 9. Put pipe back on and add oil (225 ml (7.6 oz) Cobra 3 Shoe Clutch Milk (Part # MCMUGF01). ES4: Ignition Stator care: Stator failure will r esult from r[...]

31 stator. • Non - resistor spark plug caps should be used. Resistor caps will result in a weaker spark that will reduce performance. • Make sure ground wires are secure. If the bike is not grounded it will not run. • Make sure connections are free of dirt. CAUTION: If the engine is hot, it is EXTREMLY important to take the ignition cover off[...]

32 5. Inspect and remove m arkings, scratches, and thread locker residue from the rotor and crankshaft. ROTOR INSTALLATION: 1. Use wicking / bearing retainer (green) thread locker on the inside of the rotor, and on tapered part of crankshaft. CAUTION: It is recommended that you apply the proper thread locking primer to the components that a re to r[...]

33 Figure 20 To remove radiator cap: 1. Turn the cap counter clockwise to the first stop and wait there for a few seconds. 2. Push the cap down and turn it further in the same direction and remove the cap. NOTE: Inspect the old coolant for visual evidence of corrosion and abnormal smell. Fill the radiator up to the bottom of the radiator filler nec[...]

34 Figure 21 8. Remove ignition cover using a 9/64” hex key (four places) 9. Remove belt retainer screw using a 1/8” hex key. (Figure 22 - item 1) 10. Remove belt retainer, water pump belt and water pump fan pulley. 11. Remove bearing retainer screw using a 3/32” hex key. (Figu re 22 – item 2) Figure 22 12. Heat engine case around area of i[...]

35 Figure 24 14. Reinstall new bearings, seal and impeller. Clean all threads and use green (wicking / bearing retainer) thread locker. 15. Using a liberal amount of grease on the outside seal, bearings and inside of case, reinstall bear ing assembly by using a 0.500” ID by 1.000” OD steel tube 2” long and tap on end of tube per figure 25. Fi[...]

36 ES6: Fuel & A ir System Carburetor : Tools recommended for carburetor service: • Small flat head screwdriver • WD - 40 • 8mm socket Figure 26 KING Carburetor Ref. Drawing REF. # PART # DESCRIPTION 1 R CMU0305 CARB SLIDE 2 RCMU0601 NEEDLE 3 RCMU0002 ATOMIZER 4 MAIN JET 5 PILOT JET 6 CHOKE JET 7 RCMU0301 FLOAT 8 RCMU0102 RUBBER CABLE CAP[...]

37 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 adjust ed. IDLE ADJUSTMENT: On the left side of the carburetor, there are two adjustmen[...]

38 have water or dirt in the carburetor bowl. Use automotive ca rburetor cleaner or WD - 40 to clean the carburetor inside and out. STOCK CARBURETOR SETTINGS The 2003 KING stock carburetor settings from the factory are: • 65 pilot jet • 94 main jet Cleaning the carburetor: Clean the carburetor in a well - ventilated area , and take care that th[...]

39 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 [...]

40 Chassis Service / Parts CS1: Wheels & Tires Rear wheel Rear wheel dampening Tools recommended for wheel service: • 13mm socket • Flathead screwdriver • 11mm wrench or socket • 19mm wrench The Cobra is the only 50cc to have the rear wheel damping system. This feature prevents engine impact shock caused by hard landings. This design al[...]

41 Rear wheel pullers Disassembly: Figure 30 1. Remove axle, and back wheel assembly. 2. Pull the rear wheel pullers out of the back of the swing arm. Rear wheel alignment: Figure 31 1. Measure from the side of the swing arm to the outer edge of the rim and make sure both sides are equal. 2. Adjust the wheel pull bolt o n the rear wheel puller to g[...]

42 Front wheel assembly Figure 32 REF. # PART # DESCRIPTION 1 HCNS1201 12mm AXLE NUT 2 KCKG0029 FORK LEG (NONBRAKE SIDE) 3 WCMU0023 WHEEL SPACER (LARGE) 4 WAKG0005 FRONT WHEEL (COMPLETE) 5 WCMU0001 WHEEL SPACER (SMALL) 6 BCKG0008 FRONT BRAKE MOUNT 7 KCKG0028 FORK LEG (BRAKE SIDE) 8 WCMU0016 REAR AXLE 2003 FRONT WHEEL ASSEMBLY[...]

43 CS2: Brakes Front Brakes The front brake is fully hydraulic . WARNING! Your front brake needs a break - in period to achieve maximum brake power. 30 - 40 stops will bring the brake to peak performance. Check before each ride: • Make sure the brake does not have any leaks by holding the lever in while checking hose con nections. • Make sure t[...]

44 Figure 33 2) Remove cotter key from caliper as shown and pull pads out. Figure 34[...]

45 3) Brake pads must be checked periodically for wear. They are also available from a Cobra dealer. The brake pad must be a minimum thickness of 2.5mm. This is measuring the pad + the holder as shown below. Figure 35 Brake bleeding procedure: 1) Remove brake caliper using 4mm Allen wrench as shown in pad removal procedure. Pry pads outward to full[...]

46 Figure 37 4) Attach Bleeding syringe as shown. Pump all air out of system until only clean oil runs out of reservoir. Figure 38 5) Rei nstall reservoir cap. Oil will overflow in the process. This is necessary to ensure no air is in the system. Remove bleeding syringe and quickly reinstall bleed screw.[...]

47 CS2: Suspension Rear Shock Figure 39 COBRA PART NUMBER DESCRIPTION SCKGOH01 SPRING CLIP SCKGOH02 SPACER SCKGOH03 BALL JOINT SCKGOH04 SPRING PLATFORM SCKGOH05 LOCKNUT SCKGOH06 SLEEVE SCKGOH07 BUMPER RUBBER SCKG0H08 SPRING - LIGHT SCKGOH09 SPRING - MEDIUM - STOCK SCKGOH10 SPRING - HEAVY SCKGOH11 ORING FOR BALL JOINT SCKGOH12 ORING FOR REBOUND ADJU[...]

48 Front forks Tools recommended for front fork service: • Flat head screwdriver • Hammer • Snap ring pliers • Seal drivers • 13mm wrench • 1 1/8” wrench or socket • 5 wt fork oil FORK ASSEMBLY PROCEDURES: Figure 40 1. Slide swiper (#6) onto lower fork leg. 2. Slide snap ring (#5) onto lower fork leg. 3. CAREFULLY slide seal (#4) on[...]

49 13. Connect the cartridge rod to the cap and tighten to 12 ft - lb (9 Nm). CAUTION: The damper rod is hollow and will break if the nut is over tightened (proper torque is 12 ft - lb, 16 Nm). Figure 42 Because of different rider weights, sizes and riding styles, we offer various suspension options: See Optional Components sectio n of this manual [...]

50 Troubleshooting 1) Engine not behaving properly a) Carburetor top is installed backwards (happens a lot) b) The carburetor slide indexing pin is m issing 2) Engine is down on power a) Clutch engagement is not set properly b) Jetting is incorrect c) Silencer needs repacked d) Exhaust pipe i) Has excess carbon buildup ii) Has large dent in it e) C[...]

51 Index Air Filter .............................................. 13 Brakes Front ............................................... 43 Break - In ................................................ 7 Carburetion Specifications .................................. 4 Carburetor ......................................... 36 Chain Adjustment .................[...]