I have a buddies 650 Quest(2003) that I recently replaced the valves on and when I went to start it up the first time it cranked over hard but started right up and Idled fine. I shut it off and put the filter back on and buttoned everything back up. The next time I went to start the motor it cranked over really hard and wouldnt spin fast enough to get it started, I am thinking that I may have set the timing incorrectly or the starter may be bad. I have a manual but its very vague on how to set the timing thats why Im uncertain, Im wondering what the best way is to set the timing. Also what are all the marks meaning on the back of the top timing sprocket.
Thank you in advance
Stew

 

I bet the big end of the crank rods gone very common with the quest motors .