[greghatt]

So I have this 10cc by evo, and I have about 3/4 of a gallon through it. Wicked little engine. It makes great power and is really reliable. However, the muffler sucks the big one. It constantly leaks around the extension that they put in there and creates a massive mess on my plane. I've tried the copper sealant, high temp red stuff and tightened the hell out of the through bolt hot and cold.

Now MACS has a one piece, but it's not recommended for this engine. Reports are it clogs up (the muffler) and looses RPM. And because it's on a profile, the bisson pitts just wont work. Has anyone with this engine solved the crappy muffler issue or found a replacement that doesn't sacrifice power? Failing finding something else, I'm just gonna JB weld the thing together and hope for the best.

[mwavesdave]

I emailed Tom Batty, to see if his Evo is having any issues. I'd think there might be an issue with the machining of either of the mated surfaces, which might be causing the problem.

[mwavesdave]

Greg, from Tom:

It is normal (if he checks on-line, he will see the threads).

I have had to tighten my muffler a couple of times, but nothing too serious.

Most people blame it on the 20:1 mixing ratio used for the fuel, but to me it isn't a big deal.

Cheers

Tom

[greghatt]

I know it's normal, and that's the problem. It's not just gunk coming from the exhaust outlet, it's the extension piece in the middle that's profusely leaking. And on top of that, no matter how tight I get the bolt/nut, the rear part rotates constantly. I think i'm just gonna JB weld the muffler together and see what happens.

[aceplant00]

can you get away with removing the smooth extention peice.

[greghatt]

unfortunately not. from what I have read, the muffler needs the exhaust volume to reach peak performance. even the Pitts is a little smaller volume and people are blocking one stinger to get rpm back.

[kip51035]

Epoxy or JB Weld, Epoxy aluminum or epoxy steel all work well. Clean well with lacquer thinners then put a lock washer under the bolt head to keep it tight. Are you aware that the nut is just a jam nut and the screw is threaded into the tail piece and must be tightened first before you tighten the nut.

[greghatt]

Well, I gave it the JB weld treatment yesterday. We shall see what happens the net time I make it out flying.

[CRAZYFAST]

Obviously it's junk, you should give it to me and I'll properly dispose of it.

[greghatt]

Nah, I can't say I agree with that, however I have a slightly used .91fx that I dug out of the dirt your welcome too