I aquired an older extra 300s aerobatic today for $60.00 with an os surpass 91fs on the nose. I turned the engine over by hand against my better judgement and noticed no compression and the bearings feel jerky. I assume I will have to replace the bearings but was wondering how to clean any rust off of the crank shaft. I was planning to hot antifreeze dip the engine components but Is there any special chemicals for a rusty crank or just go to it with a brass bristle brush. Antifreeze has never worked well on rust for me, just the caster residue. So what's the cleaning proccess for a rusty crank?