Hello,

I recently had my 150cc gy6 (phantom r4i) scooter drop a valve seat and mess up my engine. I got a replacment head (the piston was OK.)
when putting it back together how do I need to position the chain/camshaft in relation to the piston being at tdc.

there is a line on the cam gear that looks like it would be positioned parallel with the head but i am not sure. there arent any other markings other than a hole on one side of the cam gear.
let me know if anyone has some insight.

Chad

Yes, line up the marks on the cam with the head and make sure the hole side is up and the piston is at TDC.

-Mike