I need help with my crf250r '13

[nitrodude]

Hey guys. Im having problems with my bike. So in April i came across a problem at the track. A real loud knocking sound was coming from the engine. Also the rev limiter became slower than a crf450s. I also recognized a little bit of loss in top end power and at a certain of kicking down on the kickstart(tdc) its harder than usual to kick down. Can anyone help please!!! Ive been dying and am saddened that i havent been able to ride for months. Can it be my cam timing(chain loose tensioner fail)? My last problem with my bike was the cam timing and it had no compression. The mechanic said i may need to replace the tensioner. When i checked the timing at tdc the marks on the cam were off. Can this be it or the valves?

[DK662]

Most likely the cams being off time. Get them back in time. Make sure the cam chain and tensioner are withing specs first.