I did the 400EX carb swap on my 350X

[TatTooL23]

i finally did the 400ex carb on my 350X. went pretty easily. stock cable hooked up perfectly. was a little tight getting it into place but it goes without having to move or adjust anything major. once it was in place i was able to fit it onto both intake boots with no heating at all. it was nice.

the one problem was that the pivot of the choke arm was digging into the side of the plastic tube that goes from the airbox up to the frame. so when i would flip the choke lever up, the actual metal knuckle pivot part would be pressed against the air tube so hard that it wouldnt actually apply the choke. so all i did was remove that tube and heat the spot where the choke pivot made contact with it then pressed in on it with the bottom end of a screw driver handle. this made a nice indent so it would not touch the choke lever assembly at all.

so now it works perfectly. the thing starts so amazingly now! FINALLY!! i dont know about other 350X's out there but mine was a pig to try and start. i would kick and kick and kick on that thing. now i put the choke on and pump the throttle full 3 times. this utilizes the accelerator pump of the 400ex carb. so it gets fuel right there instantly and then its 2 kicks cold and its running.

i have not been able to mess with the jetting yet because i have not actually ridden it yet. i have a 42 pilot jet and a 145 main. the 350X also has a K&N air filter with 6 foam vents in the air box lid and a DG full exhaust. I have main jet sizes 150, 155, 160, 165, and 170 to try out when i can do some plug chops. ill keep everyone posted when i figure out what works for me.

so far seems like a really great change.

[aldochina]

cool man, gonna do this somtime, will be nice to reference back to this. keep us posted.mine is a pig when cold, but man, its like a different machine in the warmer months. very easy to start!

[booblinker]

Mine starts pretty good already, I have a 400ex carb sitting on the shelf ready to install when I put the after market exhaust on

[jrsqlc]

with stock motor im guessin you will be in the 140-155 range withthe main
when cold 2 of my X's are pigs to start. about 5 pumps of gas and a few kicks and were off.

[TatTooL23]

Cool thanks man. Any thought on all the 450 parts?? Or did i scare u with the itemized price list?? Let me know.

[Dirtcrasher]

My 25 yo motor is untouched aside from a clutch. It starts in 1-2 kicks and has been jetted for a ST exhaust and open lid.

I bought a 400EX carb ages back, never used it and just bought a rebuild kit for it this week.

I'll be breaking in my crate motor with the crate carb (roughly jetted), but I look forward to using the 400EX carb once I'm happy with the break in.

I'll post up what I find works well on the 400EX carb with my mods as well.

Thanks to Jeff for all the jets!!