Exhaust/Engine Seal??

[J-S-Q]

Hi,

I've got an OS 50 Hyper and a Zimmerman muffler. I'm just running it in at the moment and all is fine except I have noticed that there can be a bit of fuel leaking from the seal between the engine and the muffler. I have one gasket in there at the moment that came with the muffler. I've already been advised to tighten the bolts when the engine is hot but is there anything else I can do? Perhaps some kind of sealant?

Thanks.

[stg099]

I have an MP5, which doesn't have a gasket and I used a thin layer of hi-temp RTV (available at any auto parts store) per the manual. So far, no leaks whatsoever.

[J-S-Q]

Thanks for the rply. What is RTV? I haven't heard of that?

[heliMark]

ultra-copper is the name on the tube I picked up from pep boys for this application, works well, just dont apply too much too close to the opening, i understand extra can get sucked into the motor?

M3

[BarracudaHockey]

You don't need RTV, it can get sucked into the motor and will instantly snuff the plug, usually at the very worst moment.

Just clean the mating surfaces, ditch the gasket, and bolt it together. Fly it till its warmed up, snug the bolts while its warm and you're done.

If you are still getting leaks a very thin smear of 5 minute epoxy will fill in the imperfections but in a lot of years and a lot of engines, I've only had to do that once to an old 46 with a crappy muffler.

[c_forthofer]

RTV is short for Room Temperature Vulcanizing. Its a type of silicone that cures when exposed to air (specifically moisture in the air). There are other types of catalized silicone (think 2 part expoy) that have a A and B component that need to be mixed to cure. Any way you slice it all of the Silicone sealants sold in tubes ready to dispense are RTV the stuff will snuff glow plugs if sucked into the engine. I would take Baracuda's advice and stay away from it as a exhaust gasket replacement. You can get sheets of gasket material at the autoparts store and make one of your own as another option.

Chris.