A similar 49cc 4 stroke produces a similar 3.2 HP, however the 3-speed clutchless semi-automatic transmission on the CRF50F is a bit more sport-oriented, so this bike can accelerate a bit harder. The ...

These street legal motor bicycles are equipped with high quality 49cc / 4 Stroke engines and reach speeds up to 30 MPH and get 150 MPG. Standard Equipment & Features: ...

49cc 4-stroke engine features a new piston design, lighter con-rod and 3 chamber exhaust, so it produces more torque but remains compact, lightweight and reliable.