XR650R new header?


6 replies to this topic
  • mikesbaron

Posted April 01, 2008 - 10:45 AM

#1

Currently my bike has the stock header and Pro Circuit slip-on. I'm wondering if I should look to junk the heavy, cobby welded header for something else?

My main concern and besides weight is maintaining/gaining low to midrange.

  • Blownaway

Posted April 01, 2008 - 02:57 PM

#2

I have the same slip on with stock header. I thought the 650R's didn't have the header weld problem like the XR400's?

  • martinfan30

Posted April 01, 2008 - 04:21 PM

#3

I have the same slip on with stock header. I thought the 650R's didn't have the header weld problem like the XR400's?


OOPS...

I could have sworn the title said 650L...:prof:

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  • Thumpage

Posted April 01, 2008 - 04:35 PM

#4

I thought the 650R's didn't have the header weld problem like the XR400's?


You are correct. They are smooth. No weld beads on the inside to grind down.

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  • Thumpage

Posted April 01, 2008 - 05:00 PM

#5

Currently my bike has the stock header and Pro Circuit slip-on. I'm wondering if I should look to junk the heavy, cobby welded header for something else?

My main concern and besides weight is maintaining/gaining low to midrange.


If your priority is maximum low-end with great low/mid -midrange then stick with the stock header with your aftermarket muffler. If you want great midrange pull that keeps on pulling further into the upper RPMs then a aftermarket header will be what you would want. There is just nothing like the stock header for bottom end grunt if that is where you ride most of the time. Don't get me wrong, with a aftermarket header the 650R still has alot of lowend muscle without a doubt, just not quite like with the stock header. A larger tubed header will not keep the same "Super Grunt", ('Kranny' came up with that saying) right above idle. As I have mentioned before, the stock header gives a spike of power right off idle that will be lost with a larger header. The offset is you gain a good rush of power from midrange on up. The question is whether you need it or want it.
If you are mainly trail riding, you don't [need] a larger header. It would be just something you want for other faster open riding conditions and/or for it being stainless & lighter.

  • Krannie McKranface

Posted April 01, 2008 - 07:06 PM

#6

I went to a FMF High-flow with my already installed FMF Powercore4. I gained 10 more mph on the top end, but it does no feel like there is any more power. It DOES run MUCH smoother, idle smooter, start easier, sound better, and has more throttle response in the mid.
The change in header primarily added over-rev, and flattened the powerband.
It surely runs more 'clean' and never stumbles anymore.

  • Thumpage

Posted April 01, 2008 - 10:21 PM

#7

I also run the FMF Hi-Flo header and my bike has gained a definite rush of power in the midrange. My header is mated to a White Bros. Promeg muffler. Different header/muffler combos will make for somewhat varied power character but the addition of a larger diameter header will generally give you boost in the upper rev range at the very least.





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