The doctorjust told methat I'll need surgery to remove the s#!t-eating grin from face! Yesterday I took my first 40-mile ride on my now-340cc KLX250s. I didn't do any bonzai runsbecause I'm not that far in breaking it inyet, but I mixed up the ride with some single-track trails, dirt roads, and a little asphalt. The bike ended up being exactly what I wanted it to be.

First, let me tell you how it's set up:
- Thumper Racing 340cc kit using a sleeved KLX300 cylinder
- Bill Blue Mikuni TM33-8012 pumper carb bored to 34mm
- #140 Main Jet
- #40 Pilot Jet
- Needle Jet with clip on 2nd slot from the top
- Accelerator pump rod shortened 0.150"
- Elevation: 2400' above sea level
- Magura 1/4 throttle and cable from FSW
- Crank breather hole in airbox drilled to 7/16"
- Air inject system removed. Plugged the reed valve at the exhaust port by threading the I.D. and using an 1/8" pipe plug
- Backfire screen removed.
- Installed a K&N air filter with the airbox lid removed.
- Supertrapp IDS2 slip-on exhaust (all 12 disks installed) with custom head pipe.
- Stock gearing

I rode my modded-up DR650 to and from work yesterday before riding my KLX so that I wasn't overwhelmed with the changes. It didn't matter, I was overwhelmed! I fired the bike up and headed out. Iwhacked the throttle a couple of times in first gear, and each time, the front tire popped off the ground with authority! YES!!! First and second gear wheelies happen just by snapping the throttle open. It's not going to loop out on youor anything like that, but it will get the front in the air. Third gear requires a tug on the bars and your weight shifted, but it still comes up.

The throttle response is simply unbelievable. However, the bike is not uncontrollable by any means. I don't want you to think that it has explosive power or a big hit somewhere in the RPM range. It has the same powerband as the stock motor - just more power everywhere. Low-end powerwas what I was looking for, and I've at leastdoubled that over stock. Let me say that again. It has at leasttwice as muchlow-endtorque over the stock motor. I've only run it up to half throttle so far, so I can't comment on the top-end yet. But the amount of low- and mid-range poweris betterthan I had hoped for, and just make the bike that much more fun.

On the trails,I can now juststab the throttleand pick the front tire up and over rocks, logs, mud puddles, etc. Ino longerhave to have the motor in the upper RPM's to climb hills or get out of nasty holes.I don't have to be nearly so consciousas towhat gear I'm in either. Just give it throttle and it will tractor out of just about anything. One thing I did notice is that if your riding buddies don't like getting roosted in the face, stay behind them. I was riding in some rocky areas and throwing somegood-sizedgoonies out behind me.

I live in some pretty hilly terrain - not mountainous, but hilly.One of my complaints about my KLX in stock form was that when going up some hills on the highway, the bike would run out of steam. One long hill on my way to workrequireda downshiftfrom 6thto5th. No more with the 340 kit. I held 50 MPH the whole way in 6th gear. I actually found myself backing off the throttle going uphills to maintain that speed. Exactly what I was looking for.

The 1/4-turn throttle is a mixed blessing. The stock throttle almost felt like you had to make entire revolution to get to wide open, and that's why I boughta new throttlein the first place. The 1/4 turn throttle is much better in that regard. It took me about 10 minutes to get used to it. What they don't tell you about 1/4 turn throttles is that since it's opening theslide in half the distance of the stocker, it'salso twice as hard to twist. It feels very stiff.After myride, I could feel it in my right forearm. One benefit of the Magura is that I didn't have to take off the right mirror or move the switches. I put the throttle oncanted at about a 45 degree angle, and it cleared everything. I'll give it some time before I decide whether to keep it or not.

I've never ridden any of the new 450's, so I can't make any comparisons. Compared to my stepped-up DR650, it feels like half of the weight,better than half of the power, and has much better throttle response. Over the weekend, I got a chance to ride aXR250that I was looking at for my girlfriend. My KLXis head and shouldersabove that bike, both in power and handling.

I want to thank everyone on this forum who provided tid-bits of knowledge for this project. Especially: Nobrakes, for giving me the idea in the first place, Shadetree, whose posted jetting specs got me very close right off the bat, and Bill Blue, whose carb and advicehelped me a bunch.

Would I do it again if I had the chance? Absolutely - it's the best money I've ever spent ona bike. I would rate the pumper carb alone asa "must have". Combined with the extra displacement, the bike is now just a blast to ride. I liked my KLX in stock form just fine, but now it's a whole different (and even better) bike!

 

Sounds awesome man. But where are the pics of the ride? Come on its not nice to tease and not deliver.[8D]

 

OK, that's enough teasing... I'm buying a Bill Blue carb tonight when I get home!
I'll ask him to set it up just like yours. Except I ride from 0 to 3000 feet above sea level.

 

Trust me, you won't be disappointed. I didn't think there would be so much of a difference, but there really is. I'm not sure if my jetting is 100% on, but while riding the bike, Ihaven't noticed any jetting issues so far. After I break it in, I'll do a full-throttle run and check the plug. Good luck!

 

Now all you have to do is sell it and buy the Suzuki 400sm because thats the worlds best bike..................!

Sorry thought I'd beat someone to the punch, anyway great post and good info for us KLX guys that may down the road stepup to alittle more power, nice job on the pipe to.!

 

Another happy customer. [sm=icon_ladiesman.gif]

[sm=nxsmile.gif][sm=bounceybounce.gif][sm=bounceybounce.gif][sm=bounceybounce.gif][sm=bling.gif]

[sm=icon_cheers.gif]

 

Hey Iowa we heard you the first time, what's with the double post?[8D][8D][8D] Just messing with ya, you know that right?

 

even the new guys catch on fast around here. Mustang any dyno plans in the future for the bike?