either one ?. both are easy to check/fix. well, one is faster ?..lol. cam chain ?, that's alitte more work involved..lol.Thanks for your input, i will check as soon as i get home from work and chime back in with my findings. However would this explain a loss of power during that tick/knocking occurance. it will get going if i ease on it or it will eventually clear up but while its ticking it seems like it has less power. maybe more towards valves then? thanks