NOTE: If you have a bicycle with a one-piece crank, you will need to buy a bottom bracket conversion kit separately. Please select option above.

GasBike Racer Chain Drive Kit with HuaSheng 49cc 4-Stroke Engine

This kit features a 49cc HuaSheng motor with Clutch Flyweight for 5/8 Tapered Shaft, using a chain drive single speed transmission. This kit includes a 2 piece wide crank kit, if the bike has a 1 piece crankset a conversion bottom bracket will need to be used.

4 Stroke engine kits are very different from 2 stroke kits in many ways. Building a 4 stroke bike is a little more involved then the two strokes, the extra effort is worth it. Pull start engine, not push start like the 2 strokes. Overall this type of engine is more reliable with more power and torque. With some of the larger cc motors, the top speeds far exceed the 2 strokes. Since these motors are larger in cc they are also larger in size and weight. Almost all bicycles will need to use a wider crank setup to clear the motor, the stock arms and pedals will hit the motor when pedaled as a regular bike. One piece cranks will also require a bottom bracket conversion set as well (not included).

This style of the engine might need slight modification to the bikes and will not fit all frames. 

Advantages of 4 Stroke Bicycle engine kits:

• Use straight gas (no mixing oil with gas)
• More Horsepower
• More Torque
• Quieter Engine

This 4-Stroke Kit includes::

• HuaSheng 49cc with Centrifugal Clutch Engine (4-Stroke)
• Chain Drive Centrifugal Clutch Transmission with 10 Tooth Sprocket
• 2.5 L Gas Tank
• Gasoline Tank Switch (AL)
• Fuel Line #2
• Fuel Filter
• Improved Wide Pedal Crank
• 44 Tooth Sprocket
• Pineapple Bushing
• Accelerograph Throttle Handle
• Throttle Cable 50"
• Mounting Plate
• 415 Heavy Duty Chain
• Idler Pulley Chain Tensioner
• Chain Guard

• No load RPM: 8500 Cooling: Forced Air
• Displacement bore & stroke: 41.8 x 35.8
• Power: 1.2KW @6800 rpm
• Torque: 2.0Nm @4500 rpm
• Engine net weight: 5.2 kg
• Length x width x height: 247 mm x 225 mm x 335 mm
• PTO shaft rotation: CCW centrifugal clutch
• Crankcase oil change: 50 hours after the change, first at 10 hours operation
• Rear mount engine has closed loop fuel system. V-Frame mount does not

* Orders received Monday - Friday by 3:00 PM EST are eligible for
Same Day Shipping! Except for USPS which ships the next business day.

Our gasoline operated products are NOT compliant with Environmental Protection Agency ( E.P.A. ) or California Air Resources Board (C.A.R.B) for the use on/off Public roads. Upon purchase, the buyer agrees to use products for racing (closed-course competition) only and NOT for on/off public roads.

If you need help with installation or troubleshooting, kindly use our Builder Locator to find builders near you. Builders are experts with motorized bicycles.