No.3 pot has been low on compression since car was re-commissioned in 2013, but lately it's got a lot worse, now around half the value of the other 3. Car still running ok, so I was going to leave it till I stripped the whole engine. With the current restrictions, I decided to whip it off now to see what was happening. Following a suggestion from Hamish, today I made an adapter out of an old spark plug to allow me to inject compressed air into the pot. So rocker box off, turned en