Exhaust air leak. how much is ok?

[Ben99R1]

I added a whitebrothers exhaust to my L. I have a little air leak where it clamps together. My question is how much of a air leak is ok? Thanks Ben

[XRToecutter]

A small leak probably won't be a big issue, I would take it apart and throw in some high temp RTV(the orange, smelly stuff). Did it on mine and a year later still holding strong.

[Old Dog]

I added a whitebrothers exhaust to my L. I have a little air leak where it clamps together. My question is how much of a air leak is ok? Thanks Ben

None.

Any air leak (on the intake or exhaust side) will affect your jetting.

Have you clamped it down as tight as it will go? If so, you might look into using some high temp RTV sealant to cork it up, or make (or get a muffler shop to make you one) a spacer/adapter to stop the leak.

[Ben99R1]

I did notice that the PO had some high temp rtv on it already. Ill crack it open again this week and give that a try. On my 2 smoke I used a section of radiator hose. That fit over where the exhaust and header met. Ben

[Old Dog]

I did notice that the PO had some high temp rtv on it already. Ill crack it open again this week and give that a try. On my 2 smoke I used a section of radiator hose. That fit over where the exhaust and header met. Ben

I don't know about a 2 Smoke, but on a Big 4 stroke, that part of the pipe gets hot enough to melt/burn the rubber of a rad hose. ?

[HeadTrauma]

My past CR250 also had a rubber sleeve where the pipe and silencer slide together. On a four stroke, however, the EGTs are way too hot for rubber parts even that far back. I'm surprised that some people have success with even the high-temp RTVs.

A small leak isn't going to cause a big problem, but it would be best to get it sealed it up completely.

[Ben99R1]

I went ahead and used rtv and I got a second clamp. I have them bolted down next to each other. Ill have to wait a few days before I can test it out. Some dumb ass left the key on and drain/killed the battery(ME). I have one coming in the mail. It should be here Sat or Mon. Thanks ben

[akarob]

Is there supposed to be a gasket in there? On the stock L, there is a crush gasket there. It normally needs to be replaced when you take the exhaust apart. Whenever two pieces of metal come together to form a seal, you need a gasket of some kind.

[HeadTrauma]

Yeah, it's a big graphite(?) donut-like bushing that fits around the end of the stock header. I don't know if the WB exhaust needs it, but others have had issues when not replacing it upon installation of an aftermarket silencer.

[Kenzo]

a minor leak ain't nothing to worry about...

...FMF builds their headers with an "engineered" leak ?

[Old Dog]

a minor leak ain't nothing to worry about...

...FMF builds their headers with an "engineered" leak

Whoever owns that pipe should have returned it for an exchange or refund, if it came new that way. ?

I have an FMF PB header and it doesn't leak.

[flak]

there was no way I could get the gasket out of my stock pipe without destroying the gasket in the process, so I had a new one delivered with my new pipe - the aftermarket fitment is just as snug as the stock pipe, which helps avoid any free play between the header/pipe connection

[HeadTrauma]

Whoever owns that pipe should have returned it for an exchange or refund, if it came new that way. ?

I have an FMF PB header and it doesn't leak.

Lots(all?) of the FMF headers are like that and so is my (more expensive) Yoshimura. Mine didn't leak until it had been off a few times and even then it only ticks for a few minutes until it gets hot. The two-into-one collectors they use are quite long and make it difficult to weld from the inside. Still no excuse for not welding it before they put the collector on, though...

[Kenzo]

Whoever owns that pipe should have returned it for an exchange or refund, if it came new that way. ?

...except i got it in like new condition w/ the heat shield for $150 shipped.

I have an FMF PB header and it doesn't leak.

...that know about

...at this point the carbon build-up has just about sealed it

[Old Dog]

...at this point the carbon build-up has just about sealed it

?

It all got blown out within the first 5 minutes of running the new FCR! :banana: