[Masteryota]

No. The advancing you need for proper acceleration and fuel burn is in the ignition system. No different then the old car distributors and their mechanical or vacuum advance. The GY6 does not have an ignition advance in the engine, so it relies on the curve built into the CDI.

The timing referred to by cams and timing chain has to do with keeping the cam lobes in their place so the valve overlap and piston stroke stays in proper correlation. With out it, the valves may/will hit the top of the piston and bend and cause all kinds of havoc. Once the timing is set on the chain and cam(s), that timing does not change. The 'advance' some cam grinders refer to, are the lobes opening the the valves earlier than stock cams. Most manufacturers now refer to this a lift and duration, meaning how far the valve opens, and for how long the valve is held open. Generally speaking, lift and duration increase results in more power, but there is some serious science to getting the grinds correct for different power gains. That area, I am not well versed in.

My ATC engine has a mechanical advance on the cam housing. The weights on the advance rotate out similar to centrifugal clutch weights as the engine spins up, moving the pulse generator in relation to the pick up sensor, which tells the CDI when to fire the coil. This results in better acceleration and cleaner fuel burn. I used a GY6 CDI, which also has a an advance curve built in, but I can adjust the mechanical advance to cooperate with it.

The GY6 has a similar pick up coil on the stator, but it does not advance the timing at all, it is all in the CDI. Advanced timing can make starting easier and better performance, but too much advance results in pre-ignition, and can cause engine damage.