Keep your 139QMB engine running smoothly with this OEM two-valve rocker arm assembly from Blue Line Designed specifically for Type 1 engines with 64mm valve stems and a shorter cylinder head, this is a direct-fit replacement that restores proper valve actuation and engine timing without modification.
Not sure which type you have? Type 1 engines have 64mm valve stems and a shorter head. If your valve stems measure 69mm with a taller cylinder head, you have a Type 2 engine (made by Zhejiang ZhongNeng / ZNEN) � this assembly will not fit Type 2 engines.
Fits 50cc and 80cc engines with the following engine codes (Type 1 head only):
Don't see your engine code? If it includes "QM" or "FM" and you're running a 139QMB Type 1 engine, this part is compatible.
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