Lost my YS 63 muffler today. To be honest, I love the engine, but feel the muffler assembly is not the best I have seen. I used loctite to secure it, but it must have came loose anyway. Any suggestions for keeping my next muffler?

I hope I dont run into that. I have a YS .63 that has 5 tanks run through it. Are you going with a stock one again??

I screwed the nuts on as far as they could go, then screwd the 90 degree elbow in as far as it would go, then unscrewd the 90 as it screwed into the muffler piece. That is the only way I could get more then a few threads holding anything together.

Dru.

Pretty did it the way you did. I was concerned about it holding and I was right. Probably related to vibration, but hard to avoid on a profile. I did order the stock replacement and I am hoping I do not need to order another muffler. I am hoping for some tips.

Check at the auto parts store for high-temp. locktite.

I use the high temp "Ultra Copper" RTV by Permatex to seal and lock all my engine exhausts. I also have a YS 63 and have never had a problem. Make sure you clean it good with a solvent and it will adhere to anything! You can find it at the auto parts store.

Good luck,
Jon

Definitely vibration-related. These mufflers are also prone to the screws that hold the back end of the muffler on backing out. The engine is *incredibly* loud when this happens!

Performance Specialties used to offer a one-piece muffler for the small YS engines. I have one, and used it on my Top Cap / YS .53 combo with great success.

Another possibility - the muffler assembly from an OS .70 is thread-compatible with the small YS engines. These mufflers are very lightweight, hold on really nicely, sound better (IMHO) and are shinnier. I've been using one on my ME-109 / YS .53 combo with great success; I just installed one onto my DP Ultimate / YS .63. I haven't run this one yet, but I expect it to work just fine.

Visioneer1- Thanks for the os70/ys63 tip. How much was the O.S. 70 muffler?

Thanks for all the tips. I will look into the Performance Specialties and OS muffler before making a decision.

Well I have the copper RTV silicon already, and I have the parts that are left over from my broken O.S. 70. I was digging around in one of my misc,\junk boxs and found some lock washers that fit the pipe so I am going to use RTV and the washers.

What prop and fuel are you using??? Just wondering so I can compare itto mine with a 13X6 running on YS 20\20 fuel by Performance Plus.

Dru.

I use the same fuel and prop. Turns 10,700 rpms.

Jon

I have this same prop and engine combo on my WM Cap 232 46. I was told to use teflon tape when mounting the threaded pipe to the engine and the muffler. I have dozens of trouble free flights using this method...

Yup !
The OS muffler and Teflon tape . We have used that set up for years. Loctite has very little strength at the temperatures involved. Don't be afraid to get it tight.