About three weeks ago and older gentleman gave me some of his son’s old R/C stuff from the ’80s. Most of it is useless to me, like an old homemade battery pack and some outdated chargers. Amid the pile of stuff was a Testors McCoy .049 engine. The gentleman said that it used to run and his son had used it on a control line airplane. The engine was in real bad shape. The motor was covered in tarnish, the shaft would only turn about 3 degrees, and I later found out that the rotomatic starter spring was broken. After I got home I decided to take it apart, clean it up, and get it running.
I googled how to dismantle the engine and the best way to clean it but I couldn’t find too much. To help free up the shaft and get a lot of the gummed up old fuel out of it, I decided to soak the engine in carburetor cleaner. I was able to get the glo-plug off of the top of the engine with a pair of pliers – This let the carb-cleaner get down into the engine itself. I let the engine soak for about 6 hours. After I took it out and dried up all of the carb-cleaner, I was able to spin the shaft 360 degrees. It wasn’t very smooth, but it spun. I then found a piece of aluminum 1/16″ x 3/4″ and I used that to unscrew the cap on the back of the engine. After that I took the piston out. To do this I took a very small pair of pliers and pulled the piston connection rod off of the crankshaft. Then I pushed the piston rod up and pulled the piston out through the hole where the glo-plug screws in.
At this point I actually rinsed the whole engine in hot, soapy (dish detergent) water. This got a lot of grime that was still in the engine out. After I completely rinsed out ALL of the soap, I dried the engine with some paper towels and then let it air-dry for a while. After all of that I was ready to reassemble the engine. I then put a drop or two of 3-in-1 oil around the engine crankshaft and spun it a little to let it get down into the engine. I also put some 3-in-1 oil on a paper-towel and wiped it onto the piston. I did this because I didn’t want the inside of the engine to be filled with oil – I just wanted it all to be lightly oiled. Then I re-assembled the engine in reverse of how I disassembled it.
The engine right now is ready to start, I just have to buy some fuel. My local hobby shop doesn’t sell the right kind so I will have to find it elsewhere. I can’t wait to get it running, and I’ll keep ya’ll posted on how it goes.
Now for some pictures . . . .
Thanks for the info. I recently bought an auction lot of 12 assorted .049 motors, most of which are gummed up. Did you get yours running? Do you have any further advice?
That’s cool!
Well I haven’t tried to start mine yet. The main reason is I don’t have fuel. My local hobby shop doesn’t sell the right mix for this small of an engine so next time I go out of town I will look at some other hobby shops. I do however have some fuel for my larger .40 size engine. I don’t know if that fuel will work but I may try it soon if I can’t get my hands on the different fuel mix.
Extra advice? Ummm, not really. Just take your time not to damage anything but still thoroughly clean it. I would recommend to use a toothbrush and other soft bristle brushes to get all the grime out.
Good luck on your clean up! Let us know if you get one of them running!