Mid-level Red 66cc Racing Bike Engine


Out of stock

Mid-Level Race-Ready 66cc Bike Engine

This engine is SOLID! Built on a factory-balanced bottom end, this GT5 is roarin? to hit the track. With a professional porting job done on the cylinder and proper modification of the piston in all the right places, this engine will roar to life. There are many upgrades and additional work done to this engine so see the list below for details.

*Please note: Due to unprecedented demand for these engines, order will ship in 3-7 business days.

Out of stock

SKU: RENG Categories: ,


Mid-Level Includes:

  • 66cc Race-Ready GT5 Engine?
  • Billet Aluminum High-Compression Head (6cc combustion chamber)
  • Port-Matched Billet Straight-Shot Intake Manifold
  • Ported cylinder for advanced timing
  • Piston ramped at the exhaust & skirt trimmed at intake.
  • NGK High-Performance Spark Plug
  • NGK Water-Proof Spark Plug Boot
  • 12 ? of 7mm copper-core wire
  • 1 Racing Carburetor (with 6 total jets)
  • 1 longer-pull throttle cable
  • Studs in cylinder replaced with grade 8.8 studs & hardware.
  • This is the engine only, no kit included. Please select KIT UPGRADE for the full kit.

Select KIT UPGRADE.? Includes: Throttle, Exhaust, Mounting hardware, #415 Heavy Duty Chain...

By purchasing this engine you agree to the following statements:

  • I (the buyer) am 18 years of age or older.
  • Because these super high-performance engines generates so much power, and that power is out of my control once it is shipped, this engine has no warranty.? I guarantee that it will start up & run very well for you, and I will offer you support along the way.? Feel free to contact me about any questions you may have.
  • This engine is for racing only.? Not for on-road use.
  • I (the buyer) am responsible for ANY damages or loss that occurs.
  • The seller of this engine is not responsible or liable for any direct or indirect damage or loss that the use of this or other products may cause.
  • This engine will make me (the buyer) go VERY FAST – a helmet and ALL OTHER safety equipment must be work at all times.
  • I (the buyer) will use this product fully knowing & understanding that going fast on 2 wheels with a very fast gasoline engine attached is VERY DANGEROUS.? I (the buyer) understand and accept that doing so may cause serious bodily harm or even death.? I (the buyer) take full responsibility for using this engine in any way (intended or not intended.)

Additional Remarks:

Piston Modified for better gas flow

Cylinder Deck Lowered for More Compression (power)

6.0cc BMW High Compression Head (USA MADE)

Manic Mechanic Straight-Shot Intake Manifold (port-matched)

All hardware upgraded to grade 8.8

Heavy-Duty Aluminum Reinforced Exhaust Gasket

Copper-Coated, Port-Matched Intake Gasket

Expertly Painted with High-Temp Engine Enamel

Please note: there may be some small scratches and imperfections in the finish. This is normal, and it will not affect performance. Each engine is slightly different, and may have a different style clutch arm. They all function at the same, great level!


Please contact matt@bicyclemotorworks.com if you have additional? questions.


Additional information

Weight 25 lbs


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