Hi

What would cause an inlet valve to get so much carbon deposit on it?



Inlet Valve

Cheers
Gary

Possibly oil getting down past the stem seals.

Inlet -- oil and 30 years of low speed town driving -- cheap fuel won't have helped.

[Edited on 15/2/06 by britishtrident]

I've used my digital verniers to measure the valve stems to see if they are worn and they appear OK.

How would I check whether the valve guides are worn?

[Edited on 15/2/06 by GaryM]

I'd second the 'oil down the valve guide' option. It's a very old engine and the guides will have worn.

Worth getting fixed? Depends on how much oil you're using. If you're not using very much, then I'd leave it alone. If there's thick smoke coming out of the exhaust every time you blip the throttle, then you'd best get it done!

If you plan to convert the head to unleaded, then don't worry - they'll have to change the guides anyway if they are worn.

David

quote:

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Originally posted by GaryM

How would I check whether the valve guides are worn?

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If you have the engine apart, get the valve guides replaced. Sometimes the oil is caused by the valve stem seals being worn out. If you have a new head gasket set, then new ones should come with it.

[Edited on 15/2/06 by nitram38]

As it came from the factory xflos don't have valve guides --- the valves ran straight in the head -- less than ideal but it worked and was cheap.

Because of the hole in the head wears more than the valve, way to check for wear is try in a new valve and see how much it wobbles.
Remedial action usually means taking the head to an engine grinder ! and asking him to fit guides.

In the old days valves with oversize stems were some times used the hoe in the head was reamed out to suit.

[Edited on 15/2/06 by britishtrident]