Valve tappet adjustment

[Bob Moseley (RIP)]

Hey Tony - I thought we had been through this. You need to know if it is valves or rings so do the oil test as I suggested. It is pointless adjusting the valves if it is a ring problem.

Bob

[Mike K]

Originally Posted by Bob Moseley

Hey Tony - I thought we had been through this. You need to know if it is valves or rings so do the oil test as I suggested. It is pointless adjusting the valves if it is a ring problem.

Bob

Tony

Have you squirted some oil down the cylinder .. then re-done the comp. test ?

If it has a broken ring , stuck ring or worn rings etc.... then , after the oil squirt , the compression will come up , it seals the rings to some degree .

If the compression doesn't change , then you most likely have a leaky valve seat .

But before pulling the head off, do the valve tappet adjustment , it might be just a tappet nut come loose holding the valve open ?

MIKE

[Phil Waterman]

Tony- While checking the valve adjustment is probably a good step anyway. Have you done or thought about a leak down test using compressed air?

This is one of my standard diagnostic test prior to start tearing things apart. It is done by introducing compressed air through the spark plug adapter for your compression gauge. Each cylinder is tested at or near top dead center for that cylinder, with vehicle in gear brake on this is so the engine doesn't try to turn over. I generally set the pressure regulator at 50 PSI apply the pressure.

Listen for-

• sound of air leaking in adjacent cylinders - blown gasket possible
• sound of air leaking from carburetor - leaking intake valve
• sound of air leaking from exhaust- leaking exhaust valve
• sound of air from oil filler or crankcase breather- bad rings

You may need to vary the air pressure but if you have a real problem it will be very noticeable.

When you check the valve clearance take note of those that have decreased and if any of them have gone to "0" of course that indicates real valve wear.

[Little Jo]

Hi Mike - Bob - Phil

Some good ideas suggested there, thanks for the heads up, That has given me some further diagnostic checks to make before I start stripping down. It is always good to hear from others who have tackled the job first hand.

Cheers

Tony