I saw a jet size chart on here a while ago. Here is one, with some good reading along with it, from Dynojet.

http://faq.ninja250.org/wiki/Dynojet...sion#The_chart

 

Interesting, more so than the last chart that was posted on here.
So my Keihin #138 main is somewhere between a DJ #128 and #130 main.
Sound about right as I'm using the OE header and others running a larger header are using DJ jets in that range.

 

When I install my DJ 300 kit, I install the main jet that was marked 132. I decided to try the 128, Last night I swiveled the carb around and pulled out the main jet. I checked it out and found that DJ had miss packaged the jet and that I had actually dropped in a 140. The bike seemed to run fine. I now want to get hold of a 132 to try it out. I guess the 5 year old working in the DJ assembly line missed his nap time.

On another note. I am in the process of drilling out the airbox restriction on the crankcase vent. I am half way through and then I thought I wonder where all the crap will go after it drops into the airbox. I suppose I have to take off the carb/airbox boot to clean out the plastic chips?

 

dumb question time, our bikes came with keihin carbs stock right?

 

yuppers

 

In my opinion quit while you are ahead..that mod makes no performance gains and I wish I had never done it......we all did that mod 2 years ago because we did not know better. I don't want water, if it gets into the airbox, to drain into the crankcase.....stupid mod in my opinion....I have no idea why I did it. Just my opine, I got my vest on....so lay it on me.

 

Double post...damn.

 

Those are good points. The restriction is so small that it is hard to beleive that the vent works at all. I can see where yo uwould want to reduce crankcase pressure somewhat.
Anyhow it is a done deal, I heated a drill bit and it wandered through in seconds.
I think if you were to get enough water past your filter to get into the crankcase, you have probably got bigger problems to deal with than that. But thanks for your opinion.

 

Easier to remove the restriction in the AUS spec bikes as we get the KLX300 airboot. Did it when the motor was still tight so I can't quantify any performance gains. Just seems stupid to add a vent then insert a rubber bung to reduce the diameter to that of a toothpick!

 

That explains why my bike is running soo rich!! My DJ #132 is equal to a Keihin #142.5!!!!

I'm going to try the DJ #124..