HMF Exhaust Leak

[04'400ex'er]

My new HMF full system looks to have an exhaust leak where the two header pipes turn into one. There is black oil leaking onto the bottom pipe. The pipes are so close together that it is hard to tell if they are not welded. you think they could possibly not be welded? also, where the silencer mates to the head pipe black oil is spraying toward the motor on the frame, pipe and shock. the clamp is tight. I think I am gonna try some silicone there. Anyone have any suggestions on the leak at the head pipe? will the silicone be ok? thanks in advance.

[flattrack450]

i'll add to this... my leak appears to be coming from where the header meets the two stubs coming out of the head. i used new crush gaskets when i mounted the stubs to the head. it just seems the springs aren't providing a good seal between those stubs and the header. causes one hell of a backfire on de-cel!

same question as 400ex'r... is there a high temp sealant to fix these leaks?

[04'400ex'er]

Originally posted by flattrack450
i'll add to this... my leak appears to be coming from where the header meets the two stubs coming out of the head. i used new crush gaskets when i mounted the stubs to the head. it just seems the springs aren't providing a good seal between those stubs and the header. causes one hell of a backfire on de-cel!

same question as 400ex'r... is there a high temp sealant to fix these leaks? My bike has been backfiring a flame out the tailpipe on decel. I have herd if there is a bad seal it will cause this. it was the worst with stock pilot, then better with a 42, now with the 45 it is better than it has been but still blows a flame. Could a leak cause this?

[Chino]

Originally posted by 04'400ex'er
My bike has been backfiring a flame out the tailpipe on decel. I have herd if there is a bad seal it will cause this. it was the worst with stock pilot, then better with a 42, now with the 45 it is better than it has been but still blows a flame. Could a leak cause this?

your jetting is not right, that's what is causing your backfiring, not an exhaust leak. it takes alot of time and patience to get your jetting perfect and it sounds like your getting closer. i'm no expert when it comes to jetting i just let my buddys help me ~