so i moved to Prescott AZ today and where i lived in norcal i was at 500' now im at about 5200' and my bikes gutless!! still starts up and runs like a top but is a dog! haha oh well, by the way my jetting is 132 main and stock airfilter with lid off.

 

Been there...

I live right at 6k feet. I took the two-fiddy to GA this Christmas (~600 feet). Had no idea the thing could pull power wheelies!

 

you need less fuel now, lean'r out

 

As a baseline to start from, take whatever ran best where you were and make the main jet 10% smaller.
For the air screw, after the engine is totally warmed up and at the correct idle, turn the air screw IN until the bike starts to run rough, and make note of that position.
Then turn it OUT until it reaches the highest idle RPM. Make note of that position. Set the airscrew midway between those two. It's not rocket science methods, it's just what I've been shown to do, and has worked well.
With a cold start, if you can take it off choke after counting to 10 or less, your pilot is good.

 

hahahahahahaha thats funny

 

Hey Bake, I'm sorry. I'm not sure if I have mistaken this method (because I'm already having trouble with the A/F Screw) but the part where I have highlighted you say highest RPM, isnt it that we need to Turn the Screw in until the bike starts to idle rough, the turn it out until the engine runs rough again and set it in the middle of these two points and thats where you will get the best spot and the highest idle??

I'm just asking because if its the way you suggest its no wonder i'm having trouble with mine lol

 

Hey Guys ... the kouba screw link explains the adjustment well enough.

http://www.koubalink.com/fuelscrew.html

I found their comments on the pilot jet interesting and am hoping to prove their theory when my dynojet kit arrives.

Based on the recommendations from the "re jet help for a lazy old Man" thread, I've just ordered the KLX300 "2206" dynojet kit for my 2007 KLX250s and will be sure to share my results.