Only used in GY6 50cc engine with 69mm Inlet/Exhaust Valve.

cam holder retainer bracket and rocker arms for 139qmb GY6 50cc 4-stroke engines.

One of the cheapest ways to get real performance tuning. Working closely together with various 4-stroke scooter manufacturers, we have managed to increase engine performance and running smoothness. The result does not affect everyday drivability while still offering smooth running and durability. Only used in GY6 50cc engine with 69mm Inlet/Exhaust Valve. Please check the length of your Inlet/Exhaust Valve.