Couple questions about FMF exhaust system!

[KTMrider03]

I have an 07 KTM 450 SXF and I am looking at buying a new exhaust system for it. What I am looking at getting is an FMF Ti Megabomb header with a Factory 4.1 muffler. I just have a few questions to ask from anyone who has this system or has experience with it.

What are the power gains over stock?

How does the powerband change? (more low end? more of a hit?)

How much louder is it than stock?

Any feedback would be greatly appreciated. Thanks!

[VilleKTM]

Don´t forget to re-jet or you won´t find all the power a pipe is capable to offer.

If you don´t already have a JD kit run ,don´t walk ,to the dealer to get one.

[KTMrider03]

Don´t forget to re-jet or you won´t find all the power a pipe is capable to offer.

If you don´t already have a JD kit run ,don´t walk ,to the dealer to get one.

Thanks. I have my mechanic doing it for me, so I'm sure it will be all set up properly.

Any opinion/experiences with this FMF system?

[ktm231]

I have this system and have ridden it back to back with the stock setup. There is a big difference especially down low. It is louder than stock, but so is every other system out there. I have the JD kit as well as a big bore, but I also ran the system without that stuff and it was just as good.

[moabrules1]

I just put on a megabomb header with my race ready kit FMF muffler (which is a Factory 4.1 I believe). I've ridden 2X with it. I haven't touched the jetting although I am running the JD kit. It's been in the low to mid 40s (F) during those rides. Overall, I'm pleased with the change. The pipe seems to let the bike turn over a little faster and it did boost low end power a bit. Nothing earth shattering but, satisfactory. I would say that the difference is not as distinct as it was with my 05 CRF but, I did have a hotter cam, and porting so, that could be the difference. A good thing is that it didn't turn the bike into an arm jurker. After I fit my Honda with the exhaust, that thing had a violent hit, which is all well and good when you're trying to impress your buddies but, it doesn't translate into faster lap times. In my opinion, it didn't seem to rob from the topend pull which is good because that's something I really like about these bikes. I'd say I'm clearing jumps a bit easier with it. As far as the noise goes, I'd definitely say that adding the mega bomb reduced the noise level. BTW, what jetting changes should I be doing with this set up? Fatter main only? I'm at 4500 ft and I run the red needle, 45 pilot and I think the main spec'd is 180. I basically run what JD says to run in their guide.

[VilleKTM]

I have an aftermarket pipe on mine too (Akrapovic) and i also , of course , run the JD jetting but i´m far from the recommended settings. First of all i have the blue needle set at 4th pos. vs. rec. 3th. I also run 195 MJ (you read that right) instead the recommended 185. The more open pipe does increase the flow so going up in the MJ is almost always needed. I would go as far as to claim ALWAYS needed.

I convinced Bassic to try the different needle pos. as well and you can ask him how he felt about it. I don´t know which needle you run on your altitude and in which pos. but i would lower the clip one pos. and try it.

I don´t know what difference it makes in your case but my bike gained a healthy dose of low end /mid-range torque and power with the clip pos. change.

Try it - it doesn´t cost anything ,except little time , and you can always go back if you aren´t satisfied. I would definitely try a bigger MJ in your case as well.