05 450r carb on a 440ex jetting

[Js7bla]

ok i installed a 05 450r carb on my 2000 440ex, it wont idle, it back fires, it shoots flames out the exhaust, when you hit the gas and let off it wants to stay rev up for about a sec before if idles back down, i been all the way up to a 190 main and left the stock poilt jet and nothing runs bad, the header get cherry red as soon as u crank it up but when u hit the gas it wants to die like its way to rich, i dont have the hotstart plunger and spring in it as it didnt have it when i bought the carb i just put a screw in it, would that be the problem, any help i would really appricate it


my mods
440kit
stage 3 hotcam i think its stage 3
white borthers header with a curtis sparks x-6 end pipe
head has been ported
kn air fliter with no air box lid

[supertrooper90]

you probably didnt plug the hot start correctly. there is an air passage that runs from fron to back for the hot start. Take the carb off shut the butterfly all the way and blow through the back of the carb yoou will see what I mean. Also you probably want a 50 or 52 pilot jet.

[Wheelie]

Plug the hotstart correctly with the spring and plunger setup. Until then don't waste any more time trying to jet it.

[Js7bla]

Ok thanks for the replys but about the hotstart do you just plug the hole where the cable goes in the black plunger or do you plug both the hole in the carb and the plunger once again thanks

[Thumpin440ex]

People have done it both ways, use the plunger with RTV or just used rtv. I played it safe and use the plunger also.. My bike actually ran fine. Started every time with no choke.. I did however fine tune some, jetted it to a 185 main, 2 1/4 turns on the A/F needle.. Prob could use a needle adj but for the most part is really close..


John