kooper271

Hello all,
I have a 1990 RX7 vert and it has had a tough time starting. I checked the compression and got 60 psi for each burst on the rear rotor. My question is can something else be causing this besides a blown seal? My battery isn't at full strength and I think my starter and alternator may be going bad. Just looking for hope.

RotaryEvolution

iTrader: (30)

the test should be done at close to 250 cranking RPMs, if its cranking slow then your compression figures will be low. you should also always do it with the throttle held wide open, with both leading plugs removed even though you're only testing one chamber at a time the open rotor will allow the engine to turn faster, with a fully charged battery and a battery charger on high to assist.

broken apex seals result in nearly 0 compression, but worn seals/housings will cause it to be severely low.