XR650R throttle response question???

I got a chance to swap XR650R's with my dad today, i rode his 03, and he rode my 07. I was rolling on a few 2nd gear wheelies and was amazed at how much better his was than myn. My 07 XR650R feels fine, feels just as fast, but if you snap the throttle just a little its not as responsive. Infact it only pulls up a few inches to a foot in 2nd, while my dads can easily be picked up 2-3 feet. The wierd part is yanks up hard in 1st, same as his. They really are almost identical in power.

They both have the same uncorking mods, althought myn has 172 main jet, and im not sure what the 03 has on it. Im quessing this throttle response problem is due to jetting???

oh, my dads has a uni air filter, and my'n stock, wasnt sure if that could really make that much of a diffornce.

any thoughts?


His 03 uncorked prolly has the 175 main.

I gotta get one of those Uni filters.

Another item pointed out by California bud, Rich Glamis Tracy, is location of rear axle - if yours is further back harder to wheelie. Diff tire compound prolly makes diff also. So many variables, so many results!

If your dad's bike has a Uni, they come with their own back plate, so you can eliminate the stock, restrictive, backfire screen. If his bike doesn't have the backfire screen, this can easily make his bike much more responsive.

As sommer pointed out, the 650R is very sensitive to rear axle placement. The shorter that you can keep the wheelbase, the better!

I am also wondering, does your bike have the smog system on it? Many, if not all, '07 Hondas got the California smog injection on them. If your bike still has this god awful contraption, that will mess with your throttle response as well.

Is the gearing the same on both bikes?

ok smog stuff removed, theyve both been changed to XR's only less restictive airbox screan.

Both bikes have 15-45 gearing (up 1 in front, down 3 in rear) and both rear axles are even with the 4th outa 5 lines.

also if you guys have any other idea's about how to get more power that would be great, ive thought about high comp piston but im trying to save for a 450 racer, same goes for carb and cams. I might buy XR's only high flow side panel to get more air in, and do 175 main instead of 172.

Rear end sag. Are they both the same? .. Tire wear?..

my dads is definatly softer, but i cant imagine making myn softer...it already bottoms out and hits my licence plate from a jump 4 feet high.

His is broken in, yours ain't.

I really don't have anything to add other than "myn" is spelled "mine".:thumbsup:

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