Has anyone had any problems with their chain tensioner. The reason I asked is because I had a problem with my kx450f not starting. I needed some other work needed to be done other than the starting problem so I took the bike to a local mechanic. The mechanic said the bike jumped time. I assume it was for a stretched cam chain. He replaced the chain. He also adjusted my valves. Since the mechanic worked on my bike, I didn't check the valves (work was done in August). Recently the bike was getting hard to start so I thought the valves needed adjusted. When I was checking the valves, I noticed the timing chain was one tooth off. Also, the left exhaust was .016 and should be around .008. I have two possible conclusions. One is the bike still started one tooth off because it was hard to start since getting the bike back from the mechanic and has gotten harder to start recently due to the weather OR the bike jumped time again which I would have to say could be caused by a weak chain tensioner. Any thoughts?