How long should I ride before I need to do a complete check on the valve clearance? I bought the 450 new the first part of may and have about 25-30hrs on it. I bought this bike because of the reliability issue. I have been a 2stroker for years and been able to do most of the work myself, but I have to admit that this thing scares me to work on!! I just want to keep it in the best shape possible. I don't have problems with the jetting, that is not to bad. But engine work on a thumper is a little intimidating!! Should I not worry about it and just keep the engine oil, oil filter, and air filter fresh?