I have a 2001 yamaha xlt 1200 and the last trip out on the lake it started bogging down and wouldn't go over 45. I started tearing into it and found that two power valves had broken at the shaft and were worn pretty bad on the blade end.

After taking off the cylinder head and inspecting the cylinder there didn't seem to be any damage. There were no dings and the cross hatching was still visible all around. I also looked in the power valve port with a mirror and there didn't seem to be an damage to the piston or the rings. Is it possible that even with the worn down powervalves that no significant damage occurred to the piston or cylinder, and if so, can I just replace the power valves and ride on (considering I really don't have the money to do anything major on it right now)?

Thanks for the help