When I had about 85 miles on the new top end we got on a paved road to go back where the truck was parked. I worked the speed up slowly to make sure nothing would go wrong went to 65 MPH let the speed go back down to to 45 MPH then I took it to 75 MPH there was still throttle left. We are running stock gearing. When we run the bike on the dyno no wind resistance it hit 92 MPH not wide open throttle.

 

This is exactly what I was looking for, I guess I wanted real world experience. Thank you for the reply, it looks like this will be a definite for when the tax return gets here!

 

marty got his 331 up to 100mph

 

That was with the OEM speedo. True top speed was about 90mph. You're not gonna get to an honest 100mph on this style of bike unless you are pushing about 40hp.

 

I'll shoot for 100 after all this snow melts in june!

 

The 92 MPH was on Kevins dyno not my speedo we. Didn't run the bike to full wide open throttle so we don't have any idea what the top speed will be.

 

That's OK for ref data, but you can't really go by what the bike does on a dyno with no wind resistance.

Upright dirt bikes like this are not aerodynamic in any sense of the word. That's why you need to have around 40hp to get to 100mph...

I'd say Kevin (Kgwld) has the best chance cause his hp figure is in the ball park. He's way past anything a bolt-on kit will do though.

Let's put it into perspective though. If you're buying a large bore kit to a achieve blazing top speed, you might be getting it for the wrong reason.

 

The wife got her 09 klx250s up to 73 as indicated on the stock speedometer but since my huskys is smashed from a endo I couldn't tell what it was doing.

 

To clairify, the dyno sheet posted here is Bill's bike, not mine.
I've got 30 miles so far. It's just begging to rev past 5k. I'll ride it plenty this weekend, it's supposed to be in the 50's. I need to get about 100 miles on it before really trying out the 7-8K rev range. By indications, this kit is doing exactly what Bill wants it to do-produce lots of low and mid range torque. The big bore kit does make it rev much faster, but looking at the dyno chart, this kit is not just a Motocross style, "high RPM power only," conversion. Frankly, the KLX250 engine may have a redline at 10K or above, but you're wasting your time at anything above 8k, it's just making more revs, not more power.
I can tell you this much, we're pretty close on the jetting, Bill made an excellent "first shot at it" choice for jets, using the stock carb.
The engine/carb/pipe set-up on mine is for testing purposes, I will sort out the best configuration using those parts. My next step will be to mount a stock 300 pipe and muffler. Once I find one for sale.