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Adjusting valves,sorry it's so long.

6186 Views 6 Replies 5 Participants Last post by  Yooperforeman
When adjusting the valves,should the engine be hot or cold? The spec. is .006" but it doesn't say hot or cold? The reason I ask is because ever since I set my valves to .006" it has been too noisey for my liking,especially hot.Tonight I removed the plastics,set the gastank to the side and ran the engine until it was really warm,then quickly removed the inspection plugs and measured the clearance,MAN WAS I SUPRISED,About .011" Clearance.No wonder they're noisey.So here's what I did:I set the valves to a loose .004" when HOT then let the bike cool for about an hour,re-measured the clearance and I couldn't get a .002" in between.So as the engine heats up then the clearance gets bigger,just the opposite of what I thought.I put it all back together and went for a ride and it actually runs better and sounds a whole lot QUIETER!
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QUOTE ("Yooperforeman":24sfnbue)
When adjusting the valves,should the engine be hot or cold? The spec. is .006" but it doesn't say hot or cold?
Engine should be cold for valve adjustment.
That's what I thought but in my case the valve clearance gets bigger as the engine heats up.
I have adjusted Hundreds of valves and valve clearance must be set cold ( Below 38 deg Celcius or 100 Deg F) and valve clearance gets smaller as temp increases and this is fact for any engine not just me making it up. As the engine heats up the valve stem expands and gets longer and the clearance is taken up. You might want to recheck your clearance I would hate for you to burn a valve or start losing compression when the engine is really hot because a valve is not closing fully.
I thought mine where a little to noisy at first also so I readjusted them to a tight .005 cold and now it sounds fine and didn't hurt performance, actually the quad runs smoother since they were originally to tight from the factory.
I did the same thing, set mine to the factory settings, rode the wheeler and wow was it noisey. Went back and set them to a "tight" .006 and a "tight" .009, and it runs and sounds fine.
Has anyone noticed that the valve noise gets louder when the engine is hot? I always knew that thermal expansion should take up the valve clearance,so it should be zero lash when things are heated up,But this darn thing really has me confused.
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