just got it and it was sitting for 8 years...only the front rotor has compression.... the back one doesnt even make a noise when the plugs out... before i take the motor out and rebuild it i figured i'd ask around and see if its a known problem before i spend money on rebuilding and porting...let me know ... i'm trying the ATF test...

 

Your apex seals are probably stuck. You might try soaking them with penetrant, but most likely it just needs a rebuild.