Manifold spacer GY6, 50cc (139QMB)

What is a reed valve spacer?

The reed valve spacer is an aluminum component that is placed between the crankcase and the reed valve. It is often used on 50cc 2-stroke scooter and motorcycle engines.

what is the function of a reed valve spacer?

Adding a spacer under the reed valve increases the height of the block, thus increasing the volume available in the engine block. In addition, the spacer causes the boost ports of the cylinder to be flowed freely, which can improve gas flow and performance.

It is important that the thickness of the spacer matches your engine setup. As a rule of thumb, the larger the displacement, the thicker the spacer. Since every engine is unique, you'll have to experiment a bit to find the right thickness.

Note: When installing a reed valve spacer, it is critical that the engine is properly sealed, so it is best to use new intake gaskets or engine sealant.