Paul-

   You asked for compressions on the PPort.  Bearing in mind I have low
   compression rotors in my engine, I measured 50psi on each rotor.  This
   measurement was taken cold -- the engine was not pre-run or otherwise
   warmed up.

   Mark Supinski

   Sounds like an average.
   How was that done Mark? Did you take the schrader valve out
   of the compression tester gage and watch it pulse as you turned
   the engine over with the starter?
   --
   Paul Lamar ...No rotor no motor.



I don't have Mazda's fancy schmancy 3 face compression tester of
course.  I just ran the starter & saw what the peak was.

Mark

Ah so! That is an average. Try unscrewing the tire valve schrader
valve from the tip of the compression tester. They all have them.
That way you should see each rotor chamber as it comes around.
The peaks should be in the range of 100 to 140 even at 7000 feet.
At sea level it can be as high as 180 psi with high compression
rotors.

That is a good thing to do as one can identify one or more
bad apex seals.