I have been flying awhile now, and I have graduated from the buddy box to flying by myself. My two engines are getting used quite a bit now, and they are getting discoloration on them. Is there anything I can do to remove the discoloration? Jonan.

jonan,
You can soak them in anti-freeze in a crock pot to remove it. Take all the rubber and gaskets off of the engine, place it in a crock pot, cover it with anti-freeze (it must be the green kind and not the environmentally safe stuff), turn the crock pot on low (do not boil the anti-freeze) and let it soak. Check periodically to see if the crud is softening up. Once it starts to soften us an old toothbrush to brush it away.

There are a few warnings that go along with this. NEVER EVER use the crock pot to cook food again. It will be poisoned from the anti-freeze. Same thing with the toothbrush. Also, make sure you do this in an area with plenty of ventilation (not in the house) because the vapors are toxic.

Now with all of that said, why do you want to get the varnish off?? It doesn't hurt anything on the motor, and it's a lot of work to get it off. In fact, I would rather see a used motor with plenty of varnish on it. That way I know that it's been run nice and rich in it's life. A used motor that is all bright and shiny makes me think that it's been run lean and is probably ruin. At least that's they way I look at it. I've got more engines around here than I can shake a stick at and I don't bother to clean any of them. The run just as well dirty as they do clean!!!

Hope this helps

Ken

It's best to keep the engine clean on the outside because any varnish acts as an insulator so the engine will run hotter. I haven't tried it myself but apparently carb cleaner is very good and doesn't involve any dismantling or poisons. When the outside is clean, fit a BruLine air filter which not only helps keep dirt out but also stops fuel from spitting back out of the carb. This is the major cause of varnish in the first place.

In "Model Airplane News" a product called "Dawn Power Dissolver" was reviewed and a member of a local club tried it and said it works. I have not tried it so I am only repeating what I heard. He says all he did was spray it on, wait a little bit, then brushed the engine with an old toothbrush and the varnish came right off. He tested it on a 20+ year old Fox .35 engine and the picture he showed makes the engine look like new - all bright and shiny...

i do mine with antifreeze like ken said, but if you let it cook 16-24 hrs you can just take it outside and wash it off with the waterhose (and there is not enough antifreeze left on it to hurt anything).the gunk will just rinse off, no scrubbing, i do this for the purpose of looks, nothing uglier than a gunked up engine, and it does help with coooling like downunder said.