Hi all,
I just purchased a used OS .46 SF on eBay last week, and it ran great for the first 5 tankfuls or so, but one of the muffler bolts came loose in-flight and the engine died from lack of tank backpressure. Put the bolt back in, tightened both, and it happened again next flight. This time, I noticed that about half the threads and some locking compound came off with the bolt. Now it won't tighten at all, of course.
What are my options? Thanks.
Clean out the hole, tap it oversize and fit a fatter bolt.
That was my first inclination, but the hole through the engine for the bolt doesn't look like there's much room for error if i drill it out for a larger bolt.
I have TT49 pros and I tap the mufflers and drill out the engine to take
6-32. then I engrave 6-32 on the muffler. You could buy a Macs muffler. mk I just stripped a bolt-on engine muffler holes, dern that!(mvvs.91)
muffler bolts came loose (deleted) I noticed that about half the threads and some locking compound came off with the bolt. (deleted) What are my options?<
Stanley,
It's easiest to just replace the muffler. You can either order a new one from OS -or- order the replacement muffler for a Tower Hobbies 46. The muffler is slightly larger, and slightly louder, than the stock OS muffler. It is also less expensive (under $20.00), and your motor will make more power with it, than with the stock muffler.
Ken
You could helicoil it if there's enough material around the stripped hole. The repaired threads will be much stronger than the original one.
Ended up buying longer screws and locknuts. Works great now. What's "helicoil" ???
Helicoil works great for larger holes. I think the original post was regarding a carburetor screw, which are small diameter (like 5 mm and smaller). For smaller holes, sometimes it is just better to retap and use a slightly larger diameter bolt. Making a deeper hole helps if the situation permits without compromising function or strength.
I have also replaced a stripped out small metric threaded hole by retapping and using a slightly larger SAE bolt.
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