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Author Topic: Valve clearance and correct procedure?  (Read 903 times)


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Valve clearance and correct procedure?
« on: November 11, 2013, 06:24:05 am »
When you check your valve clearances on these AVL engines do you just do the 'finger test' on the tappets ( spinning but not too tight or too loose) which is to say the least, a bit vague.Or do you remove the petrol tank, rocker covers and measure the clearance with a feeler gauge properly. I see that this latter method is described in the service manual here - http://images.royalspares.com/part_manual/RE-Workshop_manual-II/017.jpg
Note that they state zero clearance for the inlet valve only, here. However, on this page - http://images.royalspares.com/part_manual/RE-Workshop_manual-II/021.jpg  they mention a 'decompressor setting' of 0.1mm ( thats about 4 thou, I think). I think they must mean the exhaust valve clearance don't you? Surely, there is no 'decompressor setting' on our engines?
I need enlightening on this procedure, please.

High On Octane

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Re: Valve clearance and correct procedure?
« Reply #1 on: November 11, 2013, 07:16:43 am »
Seems like most guys are doing the spin-n-feel technique.  I'm not familiar with the AVL motors so I can't say for sure, but the spin-n-feel seems to be popular throughout this forum and most all of the Bullets.

Scottie J used to own bikes.  Now he just lurks around in the dark.


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Re: Valve clearance and correct procedure?
« Reply #2 on: November 11, 2013, 07:32:49 am »

Spin and twirl. I usually make the inlet a little tighter so that it just moves with finger and thumb pressure. The exhaust a little looser; it spins. No up and down movement. There's a good set of maintaince instructions by Thumper out there. I've got to find the link and attach it.

« Last Edit: November 11, 2013, 07:40:18 am by DanB »
Suppose I were an idiot, and suppose I were a member of Congress; but I repeat myself. ... Mark Twain
2006 AVL Electra

Bullet Whisperer

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Re: Valve clearance and correct procedure?
« Reply #3 on: November 12, 2013, 07:49:46 am »
Regarding the 'decompressor setting', on the AVL engines, this is a mechanical device which actually lifts and holds the exhaust valve open very slightly. As long as you have some free play in the cable and in the operating mechanism, you should be fine. There is no way of adjusting this set up anywhere else - it is a collar around the exhaust cam follower, which is located by a snap ring. It could only go out of 'adjustment' by excessive cam / follower wear, which is pretty unlikely.