Hey guys I'm Andy. I'm from Pittsburgh PA. Two weeks ago I financed my first vehicle and it is a brand new 2009 KLX250sf. I got it because it is cheaper than a car and I've always wanted a dirtbike and never owned one and I thought this was even better! I kno it's impractical during winter time, but I only need it to get to work during the summer. I wanted a street bike and was looking at a gs500 but decided I wanted a 250 for my first bike (Other than bmx and riding a dirtbike for a whole 30seconds I have almost no experience) I went with this cuz I felt comfier ( I'm 6'2" 195lbs) than I did on the ninja 250 and it was cheaper. My I didn't want to modify it other than a TBR slipon exhaust at first, but now that I read a bunch of threads I am considering jetting it. Would this be a good idea?

P.S. I'm gonna be a senior in highschool and I'm goingto become a mechanical engineer, so I learn quickly if I'm interested and I've always wanted to learn to work on engines. I appreciate all the helpful info on his site!!!

 

Welcome to KF!
The KLX is a great ride, we got alot of folks down the hill in mole territory. When you change the airflow through the motor you need to adjust the fuel to match or else the mixture will be off. If you have changed the exhaust then you may want to rejet it to get the mix evened out. Hope it helps, the moles will know more for ya.

 

Hey Andy, a warm welcome to the forums and the greatest bike ever!!! Well at least the greatest bike in my opinion, but then again I've been known to be biased toward the bike since I got mine back in November of 05. With almost 14,000 miles on the bike, I smile every time I get on it and hit the road, trails or gravel fire roads we have here in the Northwest. Ride the bike for a while, then as you get familiar with it and read different ideas from this forum, then you can decide what to do as far as mods go. One thing that you can try is swapping out the 14 tooth front sprocket with a 13, that will lower the gears across the range and will give you a little more grunt on the trails. Let us know how things go, and you might even see what other members are from your area, PA seems to come up a lot from members here. I smell a group ride soon.

 

hahaha, welcome to KF and enjoy the new toy.

 

You only need to re-jet to correct the a/f ratio after changing something that affects it. A slip on doesn't have that much effect, but the only way to be sure is to dyno the bike. Over the counter jet kits are only a guess at the correct jets.

Rob

 

I've had the bike for 3 weeks now and have about 300 miles on it. I ride it to work every weekday and enjoy every minute of it. I just put on a TBR slip-on carbon fiber M-7 exhaust last Friday and the thing is sickkk!!! Luckily I don't think I have to rejet it. It seems to run fine. The only problem is my airbox melted a little bit, but no hole and nothing to worry about. I'll try to put up pics soon. After I get my paycheck I'm feelin an edge tail light kit.

 

Cool! Well except the air box melting, what caused that?

 

Airbox melting sounds like an issue to me. Park a little to close to a blast furnace?

 

Haha no nothing that bad. It's just that the diameter of the TBR slipon is like 3x's the size of the stock pipe leading from the muffler to the header. And the gap b/t the frame and the airbox is very small, so the new pipe is almost ( maybe 1/16" away from the airbox) vibrations probably caused them to touch a bit and caused a very small deformation in the plastic of the airbox(about 1 sq. cm.) I don't think it's a big deal tho.

 

Welcome to KF!