Quick Q about Valve Clearance?

[DesertCR]

Well Im in the middle of doing a valve adjustment and all of the valves are in spec but I was wondering if I should adjust them towards the middle or looser side of the spectrum? For ex: my intake valves are .13mm, should I put them to .15mm or .18mm? If I go on the looser side will the motor be that much louder. I think Im also going to cut off the decomp, noticed a little ticking sound lately and I think that it may be the culprit. So whats the work on valve clearance?

[ebrabaek]

Well Im in the middle of doing a valve adjustment and all of the valves are in spec but I was wondering if I should adjust them towards the middle or looser side of the spectrum? For ex: my intake valves are .13mm, should I put them to .15mm or .18mm? If I go on the looser side will the motor be that much louder. I think Im also going to cut off the decomp, noticed a little ticking sound lately and I think that it may be the culprit. So whats the work on valve clearance?

I would leave them..... If they were out of tolerances... I'd put them in the middle..... When they wear they usually will tighten as dirt is ingested... The seat will wear..... and the valves will now seat deeper minimizing the clearance..... The shims come in a 0.05mm interval.... So the 0.13mm will now become the 0.18mm size.....minimum. but practically could turn into a 0.20mm..... So you can chase your tail here..... Don't ask me how I know this....?

??

Erling

[DesertCR]

Thanks for the response. Actually Pro-x sells them in .25 increments and theyre good quality. What about the exhaust, I've got one right on the minimum at .20-.21 and the other at .23 Should I just adjust the tighter one and leave everything else alone? I think Im still going to get rid of that decomp though.

[JUNURE]

Thanks for the response. Actually Pro-x sells them in .25 increments and theyre good quality. What about the exhaust, I've got one right on the minimum at .20-.21 and the other at .23 Should I just adjust the tighter one and leave everything else alone? I think Im still going to get rid of that decomp though.

I would & did get rid of the auto decomp, is cool how fast they start without it. If it right on the minimumin I would adjust both to the middle, your going to have the cam out anyways.?

[DesertCR]

Yep cut the decomp off but nicked the cam a little, not the lobe but where the cam caps ride, hopefully its ok. Im just gonna adjust them to middle/loose and go from there, probably gonna do the primary nut and balancer loctite too, get it all out of the way!

[hinksy]

desertcr , if that " nick " is on the plain bearing surface I would get it seen to , as it could gouge out the cap and go through your motor , greg

[JUNURE]

+1 I would also be worried about that nic.

[Craigo]

You should remove the cam to remove the decomp...as you have now realised..

If you removed the cam you would have had a better reason to adjust your ex valve clearances..otherwise I would have left them.....

[DesertCR]

I did have the cam out of the motor, but unfortunately I did catch the cam and actually there is two nics:banghead:

I steel wooled the cam and it doesnt look too bad but you can catch a nail on one of them. I'll try to post a pic soon, see what ya think.

[ohgood]

I did have the cam out of the motor, but unfortunately I did catch the cam and actually there is two nics:banghead:

I steel wooled the cam and it doesnt look too bad but you can catch a nail on one of them. I'll try to post a pic soon, see what ya think.

remove the HIGH spot, if there is one, and leave the LOW spot alone. i'd use a stone myself, but some people can mess up an anvil with a rubber hammer. if unsure, find a machinist with all his fingers and ask.

[Erik Marquez]

remove the HIGH spot, if there is one, and leave the LOW spot alone. i'd use a stone myself, but some people can mess up an anvil with a rubber hammer. if unsure, find a machinist with all his fingers and ask.

THIS ^

If not a stone, then a piece of 1200-1500 grit wet / dry sand paper wrapped over a flat hard surface. If you have a very fine cut small file, that works as a backing, or a piece of 1/4 or better steel bar stock, or whatever.

And wither stone of the paper detailed above, we are talking just 1 to a few passes. You’re not trying to grind down anything.

[Noble]

Actually the decompression mechanism can be removed with the cam in a vise and a Crescent wrench on the decompression part. Breaks off rather easily. Then remove the retaining ring and the operating pin and the alignment pin. No grinding needed.

[Dylan921]

I always thought that it was spring pressure and the stock 2 piece valves stretching that tightened the valves.

Ingesting enough dirt to wear the seats to change the clearance would result in a lot more damage to the motor before the valves went out of spec.

True?

[DesertCR]

Thanks for the tips fellas, Im just waiting on some shims and I will throw her back together, let you know how it runs.

[mickeydee]

I always thought that it was spring pressure and the stock 2 piece valves stretching that tightened the valves.

Ingesting enough dirt to wear the seats to change the clearance would result in a lot more damage to the motor before the valves went out of spec.

True?

dirt being ingested thru the intake valve(Causeing premature wear on the valve seats and valves) also wears out the piston and rings at an excelerated pace

[Erik Marquez]

I always thought that it was spring pressure and the stock 2 piece valves stretching that tightened the valves.

Ingesting enough dirt to wear the seats to change the clearance would result in a lot more damage to the motor before the valves went out of spec.

True?

The clearance closing up is a function of the valve face and seat wearing and the valve receding in the head.

And that happens with and without dirt ingestion, just happens much faster if the dirt does get in.

Look at most any piston that comes out. You will see lines running up and down the piston face.. that is likely dirt ingestion, or carbon particles.