Muffinman

I just bought an MDS .28 engine. and was reading the instruction book before trying to break it in. The instructions seem fairly much the same as other engines, except for the instructions on the low speed idle needle. Ooops. I just re-read the instructions, and they said something different from what I read the first time. This makes more sense to me. I thought they said the low speed needle was on the throttle arm of the engine, It really says on the throttle side of the carburetor. So I guess everything is okay with the instructions. Anyone have any experience with this motor? Any suggestions on props or glow plugs?

Muffinman

I took it out today to run it. Using a MA 9x5 prop, 10 % Sig Champion fuel, 20 % oil, 1/2 castor 1/2 synthetic. It started with the first touch of the starter, with the needle valve out 2 1/2 turns from closed. I turned the needle valve in a little and ran it up to about 13800 rpm. After a while, about two minutes later it started sputtering a little, and ran kind of rough, then smoothed out for the rest of the tank. The instructions say the glow plug that comes with the engine is for break in only, and will burn out after a while. Could this been the cause of the sputtering? I'll try it again tomorrow with an OS A-3 glow plug and see how it runs.

Homebrewer

My Feedback: (8)

The glow plug that comes with MDS engines are JUNK and are only good for several runs only and should never be flown. They are truly break in plugs.

Muffinman

Took it out again. I changed the glow plug to an OS A-3, there was a world of difference with the new plug. No stuttereing at all. Ran nice and smooth until the tank was empty. MDS wasn't joking about their supplied plug. Said it would work 2-3 times then needed to be replaced - which was right on. They said the RPM max out about 20K. I wasn't that brave, only turned the needle to about 12500 and it sounded pretty wild to me. So I left it there. After a few more tanks, maybe I'll try to get it up a little faster.