Mikes145

My Feedback: (5)

It seems pretty common for the Magnum 91 4 stroke muffller to come loose. I just got from flying and its gone. I had some hi-temp gasket stuff on it and that didn't help. A new muffler cost around $25 but it's out of stoke at Hobby People. This muffler doesn't look too complicated. It appears that I lost the elbow with threads on both sides too, I'm guessing it's still attached to the muffler somewhere over the flying field.Anyone have an idea how i can make my own?

jester_s1

If you have a machine shop and a blueprint, it's not too hard.

Seriously though, you'd have to have a die for those threads and that tool alone would cost way more than $25. Get a new one and secure it by tying a piece of wire from the end of the muffler to the engine mount. That should keep it from turning, but even if it doesn't it does make it easier to find since it'll be dangling from the front of your plane when you land.

red head

The wire is a good idea if you keep having the problem, I've seen it done many times. Another thing that may help is to get some "TEFLON " plumbers tape and wrap the threads real good, I've been using this method for years. ENJOY !!! RED

Gray Beard

My Feedback: (-1)

I have drilled a small hole at the muffler tip and ran wire through it but it's only a catching thing. If the header breaks off at the cylinder the wire will still catch it but that is telling you your getting a lot of vibration and the muffler needs to be supported because the weight of the muffler is helping to flex the header. I have one OS .91FS that breaks headers more often them I like. Next time I use it I will make a muffler support bracket for it.

Live Wire

You put it on the way it is supposed to be and it won't come off. Hey thread it all the way and back off to fit and lock the nut