I have the head off, got a ratchet on the cam gear, but it's very hard to turn over, when the valve is at it limit, it snaps hard then frees up until it touches the other valve. Any help? I can't figure it out

 

That is how it is supposed to be, the cam lobes push the valve springs down, it takes quite a lot of force to do this. On multi cylinder engines, one or two valves will be pushing down while a couple of others will be pushing up but, on a single cylinder machine, you get all the force one way at a time. While you have the head off, check the cam lobes and follower faces for wear, and the cam bearings and rockers for wear and roughness.

 

Thanks. The valves are opening and closing fine, nothing looks bent. When the valve is all the way open, and starts closing it snaps loud and closes with a lot of force, both valves are the same way, before the other valve opens, the. can turns freely until it touches the next valve