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CRF250 fmf megabomb problem

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I recently got a FMF system which is a fmf4.1 and megabomb for my 07crf250.

I recently also put in new jets. My problem is i have a slight air leak in megabomb header where the exhaust end, not like a hole, its too big to securly fit on the exhaust port but its confirmly on so it overlaps making not a lot but small amount of air to come out of it. What should i do to seal this air leak up?

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If it is leaking at the joint you can also use chamber seal sold at local bike shops. I used it quite often in the 2 stroke days

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Is it the joint or on the head?? If it's a joint there should be a lead gasket I think

With my stock header there was a gasket, i had to remove it for my new header to fit. The leak is coming from the exhaust end btw not the engine.

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If it's leaking at the exhaust port where the header pipe bolts up with the 2-12mm nuts, there should be a copper O-ring in there. Most of the time it's smashed and doesn't seal real good. I don't know if it's the dual or single exhaust, but on the duals where the header pipe meets the mid pipe, there should be a clamp there if I'm not mistaken. I have a whole FMF system hanging in the garage at home I can ask my kid to check for sure if you need, just let me know.

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Unless there is a deceleration misfire I wouldn’t worry about it. If it misfires or is a big gap I would call FMF directly to send both pieces in and have the header expanded to make a better seal.

In the majority of cases as the exhaust temp builds the header will expand more and should seal fine.

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If it's leaking at the exhaust port where the header pipe bolts up with the 2-12mm nuts, there should be a copper O-ring in there. Most of the time it's smashed and doesn't seal real good. I don't know if it's the dual or single exhaust, but on the duals where the header pipe meets the mid pipe, there should be a clamp there if I'm not mistaken. I have a whole FMF system hanging in the garage at home I can ask my kid to check for sure if you need, just let me know.

On my stock header there is an 0 ring has slots to correctly firm the header to exhaust ports. Just an FYI i have duel exhaust and im not completely sure that the clamp that comes on it is going to fit thats why i did not clamp it on.

Im thinking about taking it off and puting my stock or different brand on it. It builds up massive heat, seems to burn something onto it every time i come back from the track.

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