I found a product at Lowe's called "Purple Power". It is a high strength cleaner and de-greaser. It costs about $8.00 for a gallon jug which will last quite a long time. All you have to do is spray it on a dirty engine, let it sit for a couple of minutes, scrub it with an old toothbrush and wipe clean. I bought a plane yesterday at our club's auction and the engine was pretty dirty. This stuff works like a dream!

Simple green works pretty good too and smells good too.

Especially when the spray bottle leaks all over the floor of your truck.

I was put onto a product named "Tal-Strip II" I got it at my local autoparts store although I'm told it's used by the avaition industry.........even has a picture of a military airplane on the label. Label says "Strips finishes & primers from aluminum and other metals" and it works great on the burnt on gum on our engines. Only about $13 for a spray can. of 15oz.

does it darken the aluminum?

i tried oven cleaner, it removes baked on castor, but it turned my engine dark

alot of modelers swear by Dawn Power Dissolver, i would need to trry it myself though