Sun Apr 02, 2017 12:01 am by FrecklesToo
With Mater, after I vaporized the piston (but before I knew it was gone from the hole...) my compression readings were 128-133# except for #5 hole...which was zero. Not a trace of compression showed, which lead to pulling the head and discovering an empty hole except for the rod and pin. Compression tests are the time-honored 1st step toward finding what's wrong with an engine. Finding an empty hole and deeply scored walls is REALLY disheartening.
If you have the stuff for a leakdown test, great! But if all you have is a compression gauge, go for it and test...just be sure you can keep the battery charged during the testing, because that and not having the carb choke and throttle plates wide open, will screw up any readings you might get. And understand there are things you can do to narrow down where a compression leak might be, like squirting some motor oil into a hole and testing again. As in...if the reading goes up, you might have a problem with rings.
Mike