W9 compression tester

Frank Caldwell · Oct 9, 2018

The spark plug hole on my W9 is larger than the plug in on my
compression tester. Does anyone know where I can get the proper
thread size?

DeltaRed · Oct 9, 2018

There is an outfit that makes adapters. don't remember who....Or,make your own. Break the porcelean center out of an old plug.Braze a fitting of the correct thread size to that old plug. BTDT. Easy.Or visit a local machine shop. a machinist can easily make you one on his lathe.

sunsettractor · Oct 9, 2018

I think the standard thread for an automotive type compression tester is 14mm, My h and O-6 international use a D-21 Champion, which is 18mm thread, not sure what your W-6 uses, but once you have verified the thread size of your plug, and your tester, you can purchase the correct size adapter from brillman.com, they ship pretty fast...Tom

rustred · Oct 9, 2018

the W9 can have either the 18mm plugs or the early w9's had the 7/8 plugs which is the W series in the champion line instead of the D series.

W9 compression tester

Frank Caldwell

Member

DeltaRed

Well-known Member

sunsettractor

Member

rustred

Well-known Member

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