Since i have the bike in bit i thought it would be a good time to finally do the valve clearances.

Only a 7 of the valves were out of tolerance. Sone as much as 0.08mm.

so instead of being between 0.21-.27mm it was 0.35mm clearance.

What kind of effect does this have on the bike? Just runs badly or less efficient?

depends on if its inlet or outlet really, and how much you been ringing the life outta it.

if its an inlet valve it will equal less f/a mix into cylinder as its open duration is less

if its outlet, as its open less and not opened as far, it can lead to burnt valves, as exhaust gases dont get out fast or efficient enough

both at very high revs can lead to a major pounding of the valves against their seats, mis shaping the pettle shape of valve inside cylinder.

valve clearances aswell as regular oil and filter changes are but the most important maintenance on the engine of the bikes. i would get it sorted and quick.

but they are pretty sturdy engine.

pretty sure i am right in the above, but if i got something the wrong way around, someone should be able to correct me :)

a good sign of valve clearances being well out is poor idling which sounds about right with what monkey says,i dont how far they would have to be out for any real bad damage to occur........like monkey says definately worth doing and keeping on top of.

If the clearances are tight or nil , the starting and idling will be poor due to low compression, tight exhausts will burn the valve seats.

Your clearances are more than I would expect, but the change in valve timing will not be noticable, just re shim them to the mid clearance, and away you go.


Dave.

I can definately say that it was idling poorly, quite irratic. It will be nice if the adjustment smooths the idling.

Sounds like what is happening to mine as well. Was planning on getting mine checked at some point soon.

Looks like I'd best get it sorted, just find somewhere cheap enough now.

If they're too out of whack and your timings wrong you can smash your valves to pieces or bend the stems and fire the valve springs off into the heads, which is nice.

Listen for abnormal noises when the engine is warm at idle. Just replaced 8 of my shims cos they were all way too thick and the clearances too small. A sharp metallic clicking sound was coming from the tappets when warm