The valves get tighter as they wear from slamming into the seats. I would suggest rebuilding top end. New piston, lap valves, shim valves and she will be good to go.
I was going to say the same thing, before u start bashing that guy for "too loose" it's far better than too tight. It gets tighter as they wear, not loose.
I’m having the same problem right now. Chasing down someone else faults. Bought the dirt bike for $800. Rebuilt the bottom end. Now the compression is hard. But it was like that when I first got it
