skywalker73
New Member
I bought one of these cheap cnc heads for my 66cc. The original slant head cc'd at 7cc's. This new cnc head is supposed to be 6cc's. Im wondering where to check the volume, at the first chamber where the pug sits, or the top of the outer chamber(see pics) The first chamber measured 4.5cc's and the entire chamber to the top measures 9cc's. my piston/stroke is stock. The bike runs good, but it seemed to be building a lot of heat in the head. After a 34mph run, the plug showed some signs of detonation. I am using a dellorto clone carb with a 65 jet, and a small expansion pipe.