Stripped Plug and Low Comp

[mike.smith]

Hi:

I have the Timesert tool and loan it out often. PM me if you are interested. Like Keith said, it really should be done before any heads are sent to a buyer.

As far as compression, the VW is a very loose engine. It was designed to be simple, with simple tolerances. It will tolerate a lot of slop. I never get 4 cylinders to pass a compression check at each annual. But every time, I fly around the pattern to warm everything up, and do the check again, and guess what? The "bad" cylinder is always good. You don't run your engine cold, so you really shouldn't care too much if you have good compression with a cold engine. Compression tests are notoriously inaccurate anyway.

https://resources.savvyaviation.com/wp- ... ession.pdf

Treat a VW with the respect an engine deserves, but don't treat it like a fine watch. That's something it will never be

[Weatherpilot]

So, In my new to me Sonex I was changing plugs and doing a condition inspection. (with my mechanic) Cyl #3 has 4psi and can hear air escaping from the exhaust. Bad/dirty/funky exhaust valve I'd guess.

Well, after this and completing the condition inspection - ran the engine. Got it up to temp. Shut it down and did another comp test.

Now reading 80/76 along with the other cylinders being in the same ballpark.

Thanks for all the info and help.

Greg.