I have an OS 77 that was previously use and its very dirty. I was wanting to know what would be a good solvent to clean it with or soak it in that would clean it up so it will stay cool. Also are the any precautions that I need to take in preparing the engine for cleaning.

Thanks
Nick

I'll link to my writeup rather than reposting it.
http://www.rcuniverse.com/showthread...698#post777318]

First of all, you cannot use anything that is caustic like oven cleaner, automatic dishwasher detergent, concrete floor cleaner. The 'Easy off' oven cleaner will instantly turn your engine black. You can never make it right again.

Common solvents used are carb cleaners and brake cleaners.

The talk of the town is antifreeze in a potpourri's pot or crock pot.

Don't boil it or it will turn the engine dark. Just heat it up to a point just below boiling and let it soak 12-24 hrs. Then use a brush like a tooth brush on it.

Take the head and back plate off. Remove the carb and do separate.

You can never cook food in the crock pot again. It will be poisoned by the antifreeze.

Good luck,

Jim

I've used the anti-freeze technique on two engines (Thunder Tigers) and it works great. However, one of the other members in my club had disastrous results.

He used a crock pot with a ceramic pot and undiluted antifreeze on an Enya engine. This engine turned dark gray! Another member who was present said that he used to use electrosol in a dishwasher (when his wife wasn't home!) to clean his engines, but when he tried to clean one of his Enya engines, the same thing happened, his engine turned gray!

Is there something in the metallurgy of Enya engines that is causing this to happen? Does anyone have experiences with other manufacturers engines

I've used the crock pot method for quite a number of Magnum and OS engines with excellent results and no change of color. I always thought the color change was associated with getting the antifreeze too hot. I doesn't have to be boiling or anywhere close to it actually. Keep the setting on low, if it has one. Mine have all come out new looking with no brushing or anything except rinsing them off and oiling them up after an overnight session in the crock pot with undiluted antifreeze.

.....too hot antifreeze will darken the engine. Once that happens, you might as well stick it in a cowl cause it won't return to original color. (not that I've ever done that)