What exactly is the procedure for running a compression test on a rotory motor...I know how to do a compression test on pisston engine, but this will be a first on my 7...does it matter if you use the leading or the trailing hole?...what would be a good compression number to look for? or a bad one for the fact...any other tips would really help me out...thanks...

 

Go buy your ordinary comp tester. Remove the release valve that holds pressure in the gauge. Take out the leading spark plugs, and remove the EGI fuse from the engine fuse box. Put the comp tester in the leading sparkplug hole in the front rotor and crank it over. You will see it bounce, all of the bounces should be very similar. About 120psi is perfect. Anything below 70-80 should be rebuilt sometime. Repeat this for the rear rotor also.

 

http://www.teamfc3s.org/info/articles/compression.html

 

damn...that seems easy enough..thanks

 

Oh btw Mazda recommends rebuilding any motor showing compression below 85. Dont expect a motor showing 70 to last much longer.