does anyone kno how to free a carbon locked engine? links would be great.

i've seen a few suggestions about using ATF and let soak over night

 

If it is truly carbon locked, then try diesel fuel or carburetor cleaner. Spray it in, the try to rock the engine back and forth. You'll probably want to remove the exhaust manifold and intake manifold so you can get to all three faces of each rotor.

Avoid ATF as it really likes to attack and swell the oil o-rings.

 

I'm going to have to disagree with you on this one. Carb cleaner does attack seals and o-rings....bad. especially the cresylic acid type. You should see what it does to rubber in just a few minutes. It'll eat the carbon off of anything though. If you are referring to the aerosol type, then it isn't as bad.

On a side note, I had resurrected a carbon locked engine with ATF. It still runs 2 years later.

 

I'm not sure how you would easily get the typical solvent-like "dunk" carb cleaner into the engine, so I was referring to the cleaner in the spray can. It's designed to be sprayed into the carb of a running engine for the purpose of cleaning the carbon deposits off of the intake manifold, valves, etc. Sold as "carburetor cleaner", "intake cleaner", and similar names. It's far less violent then the solvent stuff.

I don't recommend ATF since it doesn't seem to do anything to carbon. I had a carbon caked rotor soaked in ATF for almost a month and didn't see any carbon removal.

 

atf, does seem to work well for creating temporary compression. you could also try pull starting it.

 

CArb cleaner, I do it once a year just for the hell of it!! Mostly just when I take it out of storage every year.