I have a 1275 to install in a classic Mini. It's sitting beside the car, and last week a compression test showed almost non existent compression in three cylinders and only 25psi in the fourth. The engine was turned with a socket at the clutch end and a bit of WD 40 was squirted in the spark plug holes before spinning. Is WD 40 OK or should something heavier have been used? In any event, the head was pulled and the valves will be checked out this week. The head gasket seemed OK, but we'll get a better look at it, too. Thoughts? Thanks!

 

I can't imagine that you can get a compression reading by spinning the crank with a socket. You'd have to get the pistons to move much faster like it would with the starter motor.

A leak-down test, OTOH, is fine to do on the bench.

Rich

 

Jump the starter with a set of jumper cables and spin it up on the floor. Open the throttle WOT when doing it. I've actually run them on the floor....