Installing The 2-Stroke 48cc Bicycle Engine Kit

A) Mount CD ignition coil on bike frame, close enough to attach coil wire to spark plug. Mount as far away from exhaust pipe as possible to avoid heat damage to semiconductors in CDI module.

B) Attach CD ignition coil wires to same identical color coded wires coming from engine.

CDI ignition coil

C) Install Engine Kill Switch on the handlebar or use kill switch on left hand grip.Attach kill switch wire to white wire coming from engine. This will ground ignition and stop the engine when the red button on the kill switch is activated.

D) Route all wires away from engine exhaust heat. You may secure wires with a plastic zip ties (not provided).

Kill switch

B) Squirt oil down the cable sleeve: Route clutch cable through the ball-mount on motor with the big spring around the cable jacket and ahead of the ball mount. The big spring serves as a cable heat shield.

C) Insert cable wire through small spring and route through clutch arm and attach brass cable-end and screw. Adjust cable tension to allow very slight play in lever. Handlebar clutch lever or twist clutch must be in the released or outward position to complete this operation.

D) Activate lever a few times, and check clutch arm for slight free play again. About 1/16” free play is OK. Re-adjust if needed. Basics of clutch operation: The clutch lever pulls the cable that moves the clutch arm. In turn the clutch arm pushes a rod through the motor that pushes the clutch plate. ( similar to a car clutch.) Releasing the clutch lever engages the engine torque to the drive chain. The clutch allows engine to start, and engage or disengage engine torque to the drive chain. When the bike is in the pedal mode the handle bar clutch lever is locked inward in the catch notch. The bike then operates in default as it would without any engine. Periodic clutch adjustment is necessary to maintain efficient operation *NOTE: Cut off excess cable from clutch arm, before operation, to avoid possible interference with pedals, chain, your legs, etc. See Figure#3.

Figure 3

Be sure to check carb. air cleaner attach screws for tightness before installing engine.

Air cleaner screws coming loose and entering engine is not covered by warranty.

Procedure for attaching throttle cable to carburetor throttle slide: The small stop on the cable wire slides through the long groove of the carburetor brass cylinder slide. It held in a slot at the end of the cylinder.

The spring is placed inside the cylinder slide and is compressed when the throttle is twisted. Be sure it is seated all the way inside the cylinder. The spring then forces the throttle to return. For this to work properly the throttle must twist freely on the handle bar in both directions prior to the cable being installed.

A) Install twist grip throttle on right side of handlebar end. On some bike handle bars it may be necessary to ream out the handle ID to fit the bar so that the throttle will twist freely.

B) After installing cable inside the carburetor mount it on engine intake tube and tighten clamp screw. Mount carburetor as level as possible. Note: The air/fuel mixture screw should be preset at 4.5 turns counter clockwise from the totally closed position.

*NOTE: Do not back-off screw more than 4.5 turns or vibration may loosen the screw and cause it to fall out. If this situation occurs, stop engine immediately and replace mixture screw.

A) Attach fuel petcock to tank. Use Teflon tape to seal threads. Careful not to strip threads.

B) Mount tank on bike top crossover frame with two supplied brackets and nuts.

C) Attach fuel line from tank to carburetor.

*NOTE: Filters are contained in the petcock and in the carburetor inlet. If engine runs poorly clean the valve filter as residue from the tank may have clogged it.. It is highly recommend that a tank liner coating be applied inside the tank before installation. This product is available from motorcycle dealers.

IMPORTANT: PLEASE READ THIS: Gas and Oil Mixture for Fuel ratio

The engine is a 2 cycle design, therefore, a gasoline/oil mixture is necessary.

1st gallon…………….…...7 ounces of oil to 1 gallon gas (Do not run engine past 1/2 throttle)

2nd gallon………………..6 ounces of oil to 1 gallon gas (Do not run engine past 3/4 throttle)

Additional gallons…..…..5 ounces of oil to 1 gallon gas

*NOTE: Use only Synthetic 2 Stroke Oil to insure proper engine lubrication.

!WARNING! Remember safety first: Wipe up any spilled fuel. NEVER fuel a hot engine or smoke while fueling. This could result in sudden fire, personal injury. Always move your motorized bike at least 10 feet from any fueling area before attempting to start it. Never leave the tank fuel cap off after fueling as rain water will contaminate the fuel and cause engine failure.

MAINTENANCE SECTION

# 1. How to Adjust Clutch if signs of slipping or squealing occur:  A) Disengage clutch by pulling handle bar clutch lever inward and lock into catch lock. B) Remove right side engine clutch cover and remove small locking screw on center *Clutch Adjust Nut. C) Pull clutch arm on left rear engine inward. Back off *Clutch Adjust Nut ¼ turn counterclockwise. D) Release clutch lever and check for slight clutch arm 1/16” free-play on opposite side of engine. Readjust *Clutch Adjust Nut as required to get required 1/16” clutch arm free play. E) Tighten *Clutch Adjust Nut on clutch plate clockwise until just snug. F) Then re-install small locking screw in outer edge of *Clutch Adjust Nut. G) It's good idea to place a small gob of grease at gear mesh area. Use grease sparingly! Then replace cover. H) Squirt light grade oil down clutch cable sheathing to reduce friction and make for easy lever pull.
	*Clutch Adjust Nut
#2. Carburetor: After every 5 hours of operation check the adjustment of the mixture screw by rotating screw clockwise until seated and then rotate screw 4½ turns back counterclockwise. Depending on dusty riding conditions, clean air filter every 5 to 20 hours of operation by removing the filter cover to access the screen and element. Wash element with a degreasing agent such as Simple Green™ or Purple Stuff™. Be sure element is completely dry before re-assembly. IMPORTANT: If engine runs poorly clean tank shut off value filter.
#3. Spark Plug: Remove spark plug and inspect for excess carbon build up. Clean, re-gap to .028- .034 of an inch if necessary. Check plug after every 20 hours of operation. New spark plugs are available from your selling dealer. Be careful using aftermarket spark plugs as heat range and threads differ greatly. Extra plug is included with kit.
#4. Exhaust system: After 20 hours of operation check exhaust pipe for excessive oil and carbon build-up. Be sure to use supplied support strap to secure exhaust muffler to a solid anchor point on bike frame or engine. A) Remove exhaust pipe cap by loosening the retaining screw. B) Pull cap and baffle out of pipe. C) Clean with degreaser, rinse and dry. D) Re-assemble *NOTE: Excessive periods of low speed operation, idling or leaving fuel petcock in the “on” position during shut down periods may cause the pipe to become clogged with unburned fuel.
#5. Chain: Every time bike is ridden check the tension of the drive chain by: A) Rolling to bicycle forward to remove slack from the bottom of the chain. B) Find the center and push downward on the top of chain while measuring the deflection. C) Tighten chain if deflection is more than ½ inch.
#6. Head Bolts: Tighten all fasteners after each five hours of operation. Most important to check Cylinder head bolts : Tighten in a X pattern to 8 to 9 ft/lb. for 48cc 55cc; 12 ft/lb for 70cc 80cc engines using a torque wrench. A two piece cylinder and head design engine requires head bolts be kept tight. Important: Check head bolts before each and every long ride, vibration can cause them to loosen and blow a head gasket. Caution: Do not over torque or head bolts may break off. ( Twisted or broken head bolts due to over tightening is not covered by warranty. )
#7. Right side gears: Remove cover plate and keep small amount of heavy grease on gear train. Do not over grease as leaks will occur and also may adversely affect clutch operation. Regular greasing if required will help reduce gear wear and keep gear train quiet.
#8. Left side drive: Routinely pack grease in the shaft hole behind 10T drive sprocket and also in cover bushing hole. This will also help deduce noise.
General  Information Obey all traffic regulations.  Always wear a helmet while riding.  Remember that you are riding a motorized bicycle and other traffic may not be able to see you.  Never operate your motorized bicycle on a pedestrian through way or sidewalk while the engine is operating.  Never operate your motorized bicycle in an unsafe manner. Check local and state laws before riding on streets.  Using larger than 49cc for street use in not legal:   WARNING!  ALWAYS wear a helmet while riding.

If you have questions or suggestions, please contact us.