Ive finally got round to fitting this carb to my 2001 xr280 (with usual gordon mods, a bit of light home port n polishing and a crd end can)

I know some of you are interested how i get on with it as you can get em for about £60 compared to £280 for a mikuni tm33 pumper(cripes).

Im now undertaking the long and arduous task of trial and error jetting it.

I decided the way forward was to set it up with the pumper disconnected initially, and once its dialed in, then reconect and tune the pump.

I started with 45 pilot jet, stock needle in 2nd lowest position (second richest) and a 135 main jet.

Started and ticked over nicely

Wouldnt rev at all past 1/8th throttle, just spluttered so i figured too rich in the middle of range.

Went to central needle clip position; slightly better but still spluttered.

currently at position 2nd from the top (second leanest) and it seems to rev out nicely but has taken on that soft easy reving sound that i (perhaps wrongly) associate with slightly lean?

Still splutters and wont rev much past half throttle so next stage is to lean out the main jet. Im going to try to resist the temptation to make a big jump down in jet sizes because i KNOW its a bad idea..... il probably go to 128 and see how that goes after work tomorrow.

Oh ive found that is is just about possible to remove the needle without taking the carb off, which is good because removing the carb, and resqueezing it into the (far too small) airbox boot would take me at least an hour (christ that was a mission)