Exhaust Leak on Red Toad

[viclioce]

For the first time yesterday, when I started the Red Toad, I noticed it started leaking exhaust around the pipe at the header. This is new. There isn't supposed to be an exhaust gasket, is there? I don't see one on the parts fiche. Or am I mistaken? I thought it was just the springs which held it tight against the exhaust port? Am I missing something? This didn't used to happen. VIctor

[squid on a 300]

red.jpg (27.7 KiB) Viewed 4503 times

[viclioce]

So, is it a possibility of unevenness of the exhaust port, or could it be the edge of the pipe? If it's the edge of the pipe header, I could file it flat. If it’s the e exhaust port (it’s brand new!) I’m gonna be a little bit upset. Victor

[BrianZ]

Are you seeing smoke, pipe drool, or both?

The exhaust flange has a gasket between it and the cylinder, but high temp RTV, as suggested my Mr squid should work.

As you know, the pipe is a "sort of loose" slip fit held in place by springs, so it will always leak a bit. Once again, you can use high temp RTV to seal it up.

Brian

[viclioce]

OK. I just was worried because it hadn’t done it yet. I’ll give it a go! Victor

[squid on a 300]

Victor...if it's leaking where the pipe slips on put a ring of RTV around the inside of the header and slip it back on the exhaust flange..put your springs back on and wipe off any excess..let it cure for a day or two and you will be fine...the pipe and the flange just don't have a good seal...often times they will leak when cold and once up to operating temp they stop..had to do this on my 79 Husky rebuild recently..no more leaky weaky...I also just bought a new FMF pipe for my KTM..it has 2 O rings on the header and FMF still recommends using RTV
bob

[matt glascock]

Is it a big deal if there is a bit of leakage around the pipe/flange joint? Does it effect the performance of the expansion chamber? Finally does the presence of the RTV make future disassembly a bummer? Sorry about all the questions, but this interests me as I've noticed this effect on several bikes with slip-fit, spring-mounted expansion chambers. Thanks all!

[squid on a 300]

RTV does not dry hard...no issue with future removal...it just takes up some of the room between the worn exhaust flange and the worn header pipe and seals it better...when you take the pipe off you can easily remove the silicon and reapply when refitting the pipe...don't over apply...you usually don't need a whole lot...depending on the severity of the leak it could possibly create a bit of a performance issue as additional air could be introduced as the cylinder scavenges on the down stroke?
bob

[Dale]

Avoid getting the RTV on the inside of the pipe. Rather than applying the RTV to the flange or the end of the header, just apply a small bead around the pipe header about a half inch from the end of the pipe. I have observed RTV migrating a small bit with heat. And as stated, let it set up at least 24 hours. If you clean the pipe and flange, it will set up nicely and work very well.

[viclioce]

OK. Great to know! I was just surprised it happened. The Wombat didn’t have this issue and this one didn’t initially. So I’ll do this one and do the Green Toad before it ever gets fired up! Thanks guys! Victor

[hodakamax]

Good info gang, I'll also give this a try.

Max

[matt glascock]

Great info, fellas. My next warm(er) weather project has just been born! Many thanks!! One last bit. Do you need to prep the surfaces prior to product application and mating and if so, what solvent would you suggest? Thank you!!

[Dale]

Great info, fellas. My next warm(er) weather project has just been born! Many thanks!! One last bit. Do you need to prep the surfaces prior to product application and mating and if so, what solvent would you suggest? Thank you!!

I swab both surfaces with brake cleaner. Nothing too fancy, just to remove the oil residue.

[matt glascock]

Great. Thanks Dale!

[viclioce]

Dale. Your saying put it on the outside of the header of the pipe, not the edge of the header, right? Victor

[Dale]

Correct