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Discussion Starter · #1 ·
Looking to get the FMF 4.1 exhaust but not sure about the head pipe. I was told by FMF that the mega bomb is for low end performance and the power bomb is for top end performance. Any body that has either of these exhaust let me know what you think or just any body that can give me some info on this. Thanks
 

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I have to 4.1 slip on for the 450. Woke it right up all around. I have heard and believe that the ktm head pipe is really good and unrestrictive (really good flow). As far as the power or mega bomb idk much, but i know im really happy with just the slip on.
 

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Discussion Starter · #3 ·
I would just stick with the ktm head pipe but I'm 1 of those guys that has the popping and the little cut flame after I let off the gas. And I dont want 2 weld the thing. So thats why I was looking at just getting the new head pipe.
 

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I would just stick with the ktm head pipe but I'm 1 of those guys that has the popping and the little cut flame after I let off the gas. And I dont want 2 weld the thing. So thats why I was looking at just getting the new head pipe.

Big B is your header leaking at the joint at the head?

If so what have you tried to do to fix it??
 

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I have the FMFSPEED slip-on, nice sound, not too loud and feel i have gaind some low-end, i also had the exhaust leak and was thinking about wellding but tried hi-temp silicon instead, it still works good, no popping but i am on the lookout for some more permanent fix.
 

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I have the FMFSPEED slip-on, nice sound, not too loud and feel i have gaind some low-end, i also had the exhaust leak and was thinking about wellding but tried hi-temp silicon instead, it still works good, no popping but i am on the lookout for some more permanent fix.
FMF MEGA BOMB AND HIGH HEAT SILICONE THAT SHOULD FINISH OFF YOUR POPPING
 

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Discussion Starter · #7 ·
FMF MEGA BOMB AND HIGH HEAT SILICONE THAT SHOULD FINISH OFF YOUR POPPING
Mcracer.. Just bought my FMF 4.1 system. with the mega bomb. I was at the GNCC race yesterday and looked at Adam Mcgills and Kiser's quads and that's what they had on. So I bought the full system.. Now only if I could ride like them. lol. As for the leak not sure about the location of leak, Was told by Ktm dealer it was leaking at the head.
 

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I have to 4.1 slip on for the 450. Woke it right up all around. I have heard and believe that the ktm head pipe is really good and unrestrictive (really good flow). As far as the power or mega bomb idk much, but i know im really happy with just the slip on.
What jetting did you do?
 

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Discussion Starter · #9 ·
Not sure about the jetting, I will find out though.
 

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does anyone still get the popping on decel with the 4.1 full system installed? I had the slip on, just got the headpipe, was j/w
 

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Discussion Starter · #12 ·
does anyone still get the popping on decel with the 4.1 full system installed? I had the slip on, just got the headpipe, was j/w
Not sure really have not ridden all out yet. but with what little I rode in my back yard it did not.
 
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