Bicycle engine kit , single cylinder air cooling 2 stroke , Gen4 latest design, 90 days' warranty !! Bottom price from the fact

Bicycle engine kit , Rear friction kit , 2S or 4S troke ,90 days' warranty !! Bottom price from the factory !

 

ENGINE: F139 2-stroke engine or F142 4- stroke engine as opinion

Easy installation, Lower Fuel Consumption

New U brakect bearing, keep engine output smoothly, and larger power

New 1.25” Roller design, Diamond cutting , less friction to the tyre!

 

Rear mount friciton engine kit