I just cleaned up a 40 FP engine I had bought used a while back for an upcoming construction project. I hadn't used the engine before because the previous owner painted the engine red and the muffler blue! It was pretty gunked up too.

I tried the old crock pot and anti-freeze cleaning technique, and it worked great! After about 12 hours, with a little stirring now and then, the engine, save for one broken fin, looks brand new.

Now here is the question. When I took the muffler apart, there was no baffle in it. All the Thunder Tiger and O.S. engines I own and have taken apart do have a baffle. The exploded view I have of the engine does not show the muffler, and since I don't have another one to compare it to, I was wondering if anyone on RCUniverse knows whether it originally came installed in the muffler or not?

The older FP engines did not come with a baffle.....first one I remember seeing with one was in about '96 or '97....they run fine without a baffle......have a bit more power too.....and with no appreciable increase in noise......

The first 40FP's came with a number 843 muffler which had no baffle. Later versions came with the E3030 (I think?) muffler which has a baffle. The early 32F's first came with the baffless #843 and were later changed over to the E3030 with baffle which is what the 32SX comes with.

I wonder why the previous owner painted the engine and muffler as that would have a tendency to retain heat - not a good idea.

The engine was painted to match the Midwest AeroStar that I bought (as a wreck) with it. It was a decent paint job, but you are right about the heat. If I ever finish refinishing the plane I'll probably put a TT 46 Pro on it, so the 40 FP is now targeted for a Stangel Skylark 40 I am building. Between the heat issue and the color choices, the paint hadda go!

My only concern without the baffle is that there might not be enough muffler pressure to pressurize the fuel tank. I recently ran into this problem with a MDS 40 that I solved by bolting on a muffler from a 46 FX. I'll see how this engine runs first before making any replacement decisions.

Thanks to all for your responses.

-Stu

I take the baffle out and then take a 1/4 inch drill and open the exhaust outlet up on mine......never had a problem with pressure......

My older fp40 runs fine on the muffler that has no baffle. Not too loud either. I'm trying to find just the right plane to put it on right now. Any suggestions?

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