Hey there,
So I recently p/u'd a Q4 with a Powerbomb header for my '10 KLXs. The header lines up perfectly, but when I go to slide the flange on to the bolts, it gets hung up immediately. Rotating it doesn't seem to make a difference. There's no way to wiggle it in there either. It looks the flange itself is way to big to fit in the space when compared to stock. I referenced the header p/n: 042155 and it's correct.

Is there any way to remove the flange itself from the header? Can I grind it down slightly to fit? I don't want to ruin the thing if it was made for an earlier model.

Thanks,
Chris

 

Hoping I can be of some help here as I have the powerbomb header on my 09 sf. I'm going to assume that by the flange you mean the part that slides freely on the header and holds the header in place when bolted down, correct? I wouldn't recommend doing any grinding or cutting it off as it's needed to hold everything together, but without actually being able to see what you see, it'll be hard to say. Have you compared the flange on the pb to the stock one?

I just finished the 351 build on my klx and when I went to put the exhaust back on I had a similar issue. What helped me was working my way backwards. I mocked up the exhaust on the ground next to the bike, then loosely mounted the muffler, then the header. Turns out when I was trying to put the header on first I was routing it too high and outside of the bike instead of back through the frame. Not sure if my story of failure will help you at all, but hopefully a little comic relief.

 

Yepperoni. Thanks for the reply.

The header, I found out is from an '07 model year if that makes any difference. It's more football shaped, and no matter what angle I tried, it would not fit in the space between the cylinder wall and the exhaust mounting bolt on one side.

The stock flange from my '10 is smaller, more circular/ufo shaped, and has less material around mounting holes.

I sent some pics to FMF and will try a new header today.

 

I believe 07 was the last year for the old style plastics, so maybe they decided to change some engine specs when they updated the appearance. Keep us (me) posted on how things go with FMF and your new exhaust

 

I eventually ordered another header. The flange was a perfect fit with no issues. The clearance must have changed when the bike was updated.
Thanks for the replies!

 

Good deal, now you just have to get rid of the old header

 

I've the same set up and had the same problem, then I found a YouTube vid on how to fit, boom , put ur header on loose, then muffler, tighten from the rear to front, went on like a dream going rear to front,