I just bought a brand new Magnum 28 for a combat plane. I used a little locktite on the muffler screws, like I always do, and one of the screws broke completely in two when I was trying to loosen it. Now part of the screw is stuck in the muffler's threads, and it is stuck real good. There is no piece of the screw that is sticking out from the threads either. Is their any way that I can get this screw out?
Thanks!

Ooo. That's a tough one.

If the broken bit of screw is level with the face of the muffler you can cut a slot with a Dremel cutoff wheel thats wide enough for a flathead screwdriver. Of course if you do that yuo might damage the muffler face and end up with a leak at that point.

Time for a replacement?

I have had a similar situation in the past except that the bolt was broken off in the engine case. You can get a bolt extractor at most hardware stores. I got mine at Sears. It resembles a drill bit but it goes in a tap handle. It is tapered and has very coarse reverse threads. To use one of these you need to first drill into the broken bolt with a drill bit that is small enough that it won't damage the threads. Then you screw the extractor into the drilled hole. Remember, it has reverse threads so while you are "screwing" it in, it is twisting the broken bolt out. The more you can screw it in, the more pressure on the broken bolt.

I have had various cases of broken screw, bolts, etc over the years (not on planes) and in almost every case, I ended up drilling the screw or bolt out and tapping new threads.

You can try to cut a slot like the Vision said. Before you do, get some liquid wrench and drip some onto the screw and let it set. If you tap on the muffler, that may help the liquid wrench make it's way lower. Also, as you grind the slot, that will help it to migrate lower.

EZ outs as Aptar described, are also a good idea and work good but usually on bigger stuff. On smaller stuff, by the time you drill a hole for the EZ out, there usually isn't enough meat for it to bite into.

They are both worth trying, but factor in the cost of a new muffler and you may, unfortunately, find out the new muffler was the best solution.

Good luck!

Also, your going to need to hit that bolt with a propane torch....remember the loctite?

when the screw broke trying to loosen it, the bolt extraktor will break too (in most cases).


how i removed broken screws from motorcycle crankcases:

If the screw is level with the crankcase i lay a washer on it and welded it to the rest of the screw. cause of heat aluminium extended more than steel and in most cases it was possible to turn out the screw by grabbing the washer with pliers.

mec

Had a friend who used to race sprint cars he would put a nut over the broken screw and weld it, then use a wrench on the nut. since we are talking 6-32 or smaller that probably won't work, how about buying a left hand drill bit and drilling about half the way through, then press real hand to get the drill to bite hard and it just might come out. If you drill most of the way through, you could staybrite solder a wire into the drilled screw and try to twist it out. Best I can come up with, hope it helps or maybe gives you an idea that does work.

Thanks for the responses! I decided to just buy a new muffler, they're cheap.