[Mrturner1]

Originally Posted by davepl

Not sure what you mean by cause - but yes, if you've got a valve lashed incorrectly, it'll show up on a leakdown test. Any mechanical issue in the valvetrain, rings, and so on will show up. Basically anything besides ignition and fuel.

Ignition is much easier to fix, so start there, which was my first thing on the list! Check for arcing wires, broken porcelain, boots shorting to header tubes, all of the regular suspects.

Engines, as you know, need spark, fuel, and compression. I check them in that order when something is amiss (no pun!)

OK I just got a compression tester and a spark tester, I have a bad feeling I'm not gonna like the results of the compression tester but will know in about an hour how it looks