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Question about exhaust & tuner

4K views 11 replies 4 participants last post by  platinum350 
#1 ·
So I picked up a wrecked '08 KFX450R last night. It looks to have a tuner, airbox lid cutout & full Two Brothers exhaust. I need to find get in there and see what kind of tuner it is.

But my question is, when replacing the muffler (got damaged badly) can I slap any slip on on there or does it have to be another Two Brothers can? For some reason, they seem next to impossible to find so that's why I was hoping to be able to put something else on there and still get decent performance.
 
#6 ·
I was thinking about just the overall performance of mixing systems and getting poor results.

The Two Brothers discontinued the slip on for the KFX450 which is why they're harder to find. A FMF Powerbomb or Megabomb header will fit with all slip on systems that don't require modifying the factory header. I have a RS2 full system for 440 shipped if you decide to go with an entirely new system. Majority of the fuel controllers are universal and only show their limitations when going with an in depth build. Be sure to toss the Swiss cheese air box for a Fuel Custom intake when possible. You'll notice a huge power difference!

KB Motorsports
270-774-1982
Thanks for the info! Are you familiar with the Two Brothers header, would they be similar to the FMF powerbomb or megabomb that will accept a slip-on? Unfortunately I won't be able to take you up on that full system as this thing needs a lot of stuff and can't spend too much on full system. I recently read about the Fuel intake, sounds impressive!
 
#5 · (Edited)
The Two Brothers discontinued the slip on for the KFX450 which is why they're harder to find. A FMF Powerbomb or Megabomb header will fit with all slip on systems that don't require modifying the factory header. I have a RS2 full system for 440 shipped if you decide to go with an entirely new system. Majority of the fuel controllers are universal and only show their limitations when going with an in depth build. Be sure to toss the Swiss cheese air box for a Fuel Custom intake when possible. You'll notice a huge power difference!

KB Motorsports
270-774-1982
 
#9 ·
I'm picking up another KFX tonight, keeping one and selling the other. I'm going to see what this one has on it and see what I can swap from one to the other then decide were to go from there. The FCI sounds like the win though. I don't think I will go to crazy with the quad, I'm a bike guy but enjoy taking out a quad from time to time. One concern is noise, where I ride I don't want whichever exhaust to be too over the top.
 
#10 ·
OP back and in need of some help again. So I ended up taking the full two bros exhaust system off & replaced it with stock (wrapped) header and a Lexx slip-on. Went to start it and wouldn't start, think I ended up flooding it. Let it sit overnight and tried again this morning. Got it to start but it sounded rough, very high idle, some smoke and a lot of gas fumes. I'm assuming it's running too rich?

As it sits, it has a slip on, no airbox lid & a Power Commander 3. I'm wondering if I should just remove the PC 3?
 
#11 ·
I think i saw your thread on FB?

Check the tps connection.

If that’s fine I would just remove the pc3 because it’s not needed
 
#12 ·
Hey, yes you did! I wasn't sure where would get me the fastest response lol. The TPS connection is that in connection with the PC3? I'm not really too familiar with this quad...

I'm thinking your right, just disconnect it and sell it or keep for another bike. Is there anything needed to disconnect it, to make it stock again as far as the wiring goes?
 
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