I've also fitted ex250 carbs on my 2003 xt600e.
The pilot jet is around #38 stock, i've drilled mine to 0.45mm, in an attempt to get rid of a small lean surge swhich comes as you get on the gas just after idle. Otherwise 0.40 should have been fine. I just think the taper on the needles are slightly of for my bike.
I've raised both needles around 0.80mm as I recall, and have fitted #116-ish mainjets (from memory). My bike has oversize headers, aftermarked exhaust, and opened up airbox, and aftermarked airfilter. Perhaps I could go down a couple of numbers on the mains, dont know for sure. Stock seemed slightly lean with snorkel removed from airbox.
The carbs bolted in quite easely, both fitted nicely in the intake rubbers, and the right airbox-to-carb-hose fitted aswell. The left was too small, so i used a larger hose, squized over the original hose coming from the airbox.
Both gascables was rerouted, and was bolt on the new carb.
I made a chokecable from an universal car handbrake-cable.
Hope it all makes sence.
2003 xt600e 138.000km
1986 xt350 98.000km
JensEskildsen screwed with this post 04-22-2013 at 02:14 PM