I want to do a compression test but don't have the rotary tester, just the regular one. How do I do this and what do I look for? Thanks.

 

I believe you have to remove a certain small valve that causes the tester to hold a given reading, so you can see the readings for each rotor face. Best thing is to film it, and then watch it in slow motion.

I've never done this... just off the top of my head.... so click the "search" button like a good rotorhead and the detailed answer will be yours!

 

I used a regular tester. You can do two tests. First make sure that your tester isn't holding pressure - you might have to take out the Schrader valve in the end of it. Crank the engine over and watch the needle bounces. They should be strong (about 100psi) and most importantly even. If you get a pattern of one strong bounce and two weak ones you have a bad apex seal.

Then make sure the tester is holding pressure (put the valve back in) and do a cumulative pressure test. The needle should go up to 100psi or so on the first cycle and then slowly climb to about 125psi as you continue cranking.

HTH

J