AHHHH!!!! 7k at 55mph! That much be pretty good on the trail! With my 351 13/39 gearing my first gear runs out at 14mph. top speed (redlining) is 90mph

 

I wondered if it would be too low, but in Colorado in some off road conditions, the 14/47 was a hair too high. And not oddly, the 13/47 is pretty much like the KLX300 model's 14/50 stock gearing.

 

I currently have the stock 14/42, but 6th just won't wind out (FMF pipe, k&n filter, 125 main jet ???...according to the previous owner).

Thoughts on going to 13/42? Gearing down for the woods couldn't hurt, but wasn't sure how it would effect the top end on the highway.

 

I have 13/42. Though I do not ride on the road, did not notice any loss of top end.

 

With the 250 you don't loose any top end, if anything you might gain a mph or two, but it'll be buzzing at 9k rpm

 

9k in 6th gear? Doesn't a rev limiter kick in before then?

 

rev limit is 10.5

 

My 06 begins missing around 8k. I haven't been able to pin point exactly where it begins missing...and maybe its jetting??? Previous owner thinks he put in 125 main jet. Could a slightly larger main jet help high rev miss?

 

I get a miss sometimes too around 8k, either it's too lean and its starving for fuel, or its too rich and it starts 8 stroking. Usually happens for me full throttle 8k rpm under load.

 

Speaking only from my personal experience and not as a professional mechanic although I do play one on TV.... (OK I lied about that part) an engine missing at high rpm whether car or (4 stroke) bike engine is an ignition problem. As I say this has been my experience but I could believe it is getting starved of gas at high rpms due to jetting but it's just not something I have seen. Easy to put a new plug in it to see if that makes any difference. Plug wire shorting? I have a habit of being quick to blame electrical problems.