FMF megabomb header and Factory 4.1 System review – KTM 450 SX-F

FMF megabomb header and Factory 4.1 System review – KTM 450 SX-F

A lot of people have been asking about the FMF system I am running on the KTM 450 SX-F so I thought I would make a small review about it.

The motor on the 2014 450 SX-F is already the nicest engine I have ever used on a motocross bike. As stock it is a little choked up though and comes with a thick baffle in the end of the pipe. This keeps the noise down but the difference in performance to the FMF system is just night and day.

Installation of the Megabomb header and 4.1 Muffler was easy and took about 10 minutes. Just starting the bike up and revving it, you can immediately notice how much cleaner the bike runs. Out on the track, power was improved literally everywhere in the powerband and the bike felt lighter too. It comes with a baffle which you can put into the end of the pipe to lower the sound which in conjunction with the megabomb header reduces noise levels by as much as 1.5dB. Our track has no sound issues though so I left the baffle out as it just sounds wicked without it! The claimed power increase is around 3hp which I have little reason to doubt.

The pipe is shorter than stock to make it less susceptible to crash damage and also follows FMF’s Factory Forward Engineering philosophy of moving the muffler closer to the motor to centralize mass. I am not sure I am fast enough to notice this, but it sounds good on paper and the bike ran and handled great.

Overall I really like the 450 SX-F already as stock, but the FMF system makes it feel and run like a full factory bike.

Highly recommended.





We got some new SEVEN gear to test out at KISKA so here is a little review of that too. Around the knee area they flex brilliantly, there is no excess material and they fit very snugly but comfortably around the Alpinestars bionic knee braces I wear.  The back is also nice and high so they dont slip down and they must be the lightest gear on the market I would imagine. The fit is very athletic and is also the tightest I have ever worn. No flapping in the arms or anywhere else.  I personally liked this, but you couldn’t wear any under body armor with it.

The price is a little on the steep side though and I think one decent tip over, crash or brush with a branch or bush and the pants would surely rip as they are so light and flexible, especially around the knees. I may be wrong about this, but that was the impression I got. They do feel great to wear though. If you are loaded, want to race in the lightest best fitting gear, dont wear body armor under your shirt and want to look a little like James Stewart (before you get on the track anyway!)  I would recommend the Seven gear.

And to finish this post off here are some photos from riding yesterday.

Photos by Bjorn and Johan.


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