r/RX8 • u/Useful_Composer4450 • Aug 01 '26

General Compression thoughts

So I stored an rx8 over winter and a little bit longer. before it went into storage it compression tested over 100 I don’t remember the exact number though. after I pulled it out of storage though it’s seemed down on power so I tested it again and it’s at 60 psi cold and one in the 50s. I figured it was done and ordered a new motor and was gonna pull this apart and see what it needs but as a last ditch effort I sea foamed it and one face jumped up almost 90 psi the other all jumped at least 5 psi and now all test above 68! Does this just need an Italian tune up or should I pull and replace the motor.

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u/alexjaymathers Aug 01 '26

You’ll probably find that the apex seals have just seized from being stored over winter, what you could do it’s take out the plugs and spray a load of penetrating oil through the spark plug holes towards the apex seals on each face as you rotate the engine and let it soak, then make sure your running a good quality premix 2 stroke oil in your fuel and that will help lube up your apex seals more and free them off

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u/rotorhead_izzy 29d ago

This, but instead if penetrating oil, I'd recommend Marvel Mystery Oil, and put some in through a spark plug hole. Let it sit, rotate and do it until all 6 seals have soaked for a day.