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Ronald Hribar

Vanguard valve lash

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Ronald Hribar

My brother is having trouble with an 18 hp Vanguard.

It does not want to turn over.

Took plugs out and it turns over.

I suspect the valve lash has to be adjusted.

Read where a decompression bump on camshaft

does not work unless valve lash is correct.

I looked online and deterimined that

.005 to .007 is correct on intake, closest to flywheel

and .010 to .012 for exhaust

being that exhaust valve needs more room for expansion

How ever my contact at Briggs tells me that .004 to .006

is correct for either valve.

I also read that when one valve is fully open adjust the other.

Question is what is correct procedure and setting ?

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.004 to .006 is the factory setting. The Vangaurd is a OHV, V twin aluminum engine. It has puny little aluminum push rods for the valves.

The cylinders have much more mass and expand more than the push rods.

This will create excess hot clearance and allow the pushrods to come off the rocker arms if the cold clearance is excessive. I adjust both intake and exhaust valves with the piston at top dead center on the compression stroke.

Your brother may have push rods off the rockers, or broken push rods.

He needs to pull the valve covers and check valve operation.

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