Questions on fine tuning my '02 KLX 300

Question 1: I installed my new race tech springs front and rear and as you know there's no dang rebound adjustment on the forks!! The rebound is a little quick and I'm wondering if increasing the fork oil (I'm currently at 90 mm) will help. Also, race tech recommends 9/16" of preload on the front and that's way too much. With 9/16th, there's very little sag.

Question 2: I've done all the so called free mods and installed the Big Gun exhaust. I've increased the main jet and she runs good, however I'd like a little snappier response down low. Does the Boysen accelerator pump make a big difference ($85)? I tried increasing the pilot jet and that didn't help a bit.

Question 3: The rear brake locks up and kills the engine on steep down hills, even when I'm braking hard with the front brake. I find I've got to pull-in the clutch, rather than let the engine compression help with the braking. Actually the rear end shatters (clutch disengaged) before killing the engine. Do I just need better brake pads or am I asking too much from the rear brakes. I've got the stock sprockets and shoudl probably drop a tooth on the front . . .

Other than that, the KLX is a fun bike that isn't as slow or heavier as everyone thinks. I know I've made a believer out my 450cc ridin' buddies. :thumbsup:

1) Give the springs a little time to break in before removing the preload. Also, do you have a large amount of stiction? You may have the forks not centered on the axle.

2) You don't have an accelerator pump on the stock carb, so you can't use the Boysen cover.

3) and the rear brakes stalling the engine is common to all 4 strokes (all bikes for that matter) unless you have an auto clutch such as the rekluse. 2 strokes just restart when you let off the brake.

#1 - ESP suspension. Talk to George.

#2 - Dynojet kit. Short of a pumper, the best thing you can do for your stock carb.

Thanks for the feedback. My bike has the CVK Carb, which operates with a vacuum advance rather than a throttle slide pin. If that's true, can I actually install the dyno jet kit, which comes with a special slide pin? There's two cables coming off the throttle, which mount on the side of the carb. I don't have a manual and haven't pulled the "cap" off that is mounted over the top-center of the carb. I figured that underneath this cap was some kind of diagphram that vacuum actuated the slide pin. I'm not sure if this makes any sense and I'm hoping you know what I'm talking about. :thumbsup:


You are correct in the makeup of the CVK carb. Yes, the Dynojet needle is designed for the stock CVK carb. However, many of the needles that Dynojet has sent out lately for the KLX300 have been a little too big in diameter to fit all the way down in the slide hole. Either the hole must be enlarged or the needle sanded down where it is too snug.

Ride on


OK, I'll give it a try. Thanks.

1.)Like every one else has said just elt the springs break in, and if you dont like them then do something about it.

2.)To get more low end power got with a TM33 pumper carb you can get them from tt to.

3.)About the engine dying (I went riding yesterday and went on some knarly hills and i had to pull the clutch in i dont know how to help you there. You don't need new break pads just need to be carefull on how hard you break.

Hope this helps a little.

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