Cam chain tensioner GY6, 50cc 139QMB/QMA

Camshaft and valve timing

The camshaft and valve timing are important components of 4-stroke engines. The camshafts allow the valves to open (i.e., to draw in the mixture and expel the gases) and are driven by the timing chain, which is in turn connected to the crankshaft.

Incorrect timing adjustment interferes with valve opening and can severely affect engine performance and reliability. Therefore, we recommend to intervene only with appropriate technical know-how.

Maintenance and tuning

Maintenance and care of the elements located in the cylinder head, including valve timing, is very important. Even though the timing chain generally has a fairly long life, it is still necessary to regularly check chain wear and wear of all related elements.

Camshafts must always be in perfect condition. You can also use tuning camshafts; the shape of the cams is revised to increase the valve opening times and thus provide more power.