I have read a post or two about this maintenance task and can see there are conflicting ideas as to what this clearance requirement is or does. I read a post that claimed periodic checking and setting of valve clearances was determined by engine starting performance. This individual claimed poor starting was the signal it was time to check and reset valves. hmmm another individual/post I read believed when his/her bike began to run badly it was time to check valve clearances. hmmm Now I begin to wonder if we all know what we are actually doing and why we do this maintenance. No insults intended. Not pointing any fingers or laughing. Just thinking maybe an explanation into this job procedure would help educate us {me}. Maybe get some imput from others as to what and why this is necessary. My basic mechanical overview is as follows: valves are normally shut held this way by springs. When the engine turns the pushrods move and the rocker gear opens the valves. The duration or length of time valves are opened or closed is determined by the position and kind of cam you are running. The adjustment recommended by the manufacturer called a valve clearance is actually the clearance between the rocker gear and the stem of the valves. You are not really adjusting the valves. This clearance is neccessary for expansion. It prevents the rocker gear from hitting the valve stem and interfering with the seating/closing of the valve.Thats why the valve must be seated/closed to do this clearance. This check should be performed on a cold engine. Any clearance is better than no clearance however the greater the gap the more wear and tear on your rocker gear. Did I mention the noise? Also if you have too great a clearance you could prevent the rocker gear from contacting the valve and pushing it open in time with the cam. Thats why there is a recommended clearance which is most likely for best running and least mechanical wear and tear {damage}. If you are running with 8=10 or 6-8 thou clearance your engine performance should be the same. The valves should still operate correctly. If your bike was running ok and then begins to run badly or has become difficult to start....its most likely not the valve clearances. Unless you race, put thousands and thousands and thousands of miles on yer bike or have a mechanical failure Valve clearances should remain fairly consistent. After a fresh build and initial adjustment I have put just over 10,000 miles on my bike without resetting the valve clearances. I have checked but adjustment was not neccessary. If you find the need to frequently adjust the valve clearances there is a problem with your adjusters they are not holding. Please feel free to correct or add to this job procedure agree or disagree thanks.
Dox
Dox
