350x/400ex Carb question

[Tom12254]

Hey everyone I did the 400ex carb swap on my 1985 350x and everything went smooth, I can get thr bike to start right up on full choke, kick it 3 times with switch off full throttle then turn switch on 1 kick and starts. My question is do I need to rejet the carb? Once the bike is fully warmed up I can switch the choke on and it doesn't have any effect on how it runs (usually should bogg down and shut off) so do I need a bigger jet/more gas in the carb? Thanks for any help

[350for350]

When I go to a larger carb, the 400EX carb on my 350X for example, I switch the jets from the smaller (350X) carb to the larger one. As long as it was running fine before the switch, it should still run fine after.

[Tom12254]

When I go to a larger carb, the 400EX carb on my 350X for example, I switch the jets from the smaller (350X) carb to the larger one. As long as it was running fine before the switch, it should still run fine after.

Thanks for the tip I'll start there! The only thing I've changed other than the carb is I put a supertrapp exhaust on it also. So stock jetting might work

[350for350]

I don't think that you considered the part where I said "as long as it was running fine before the switch, it should run fine after the switch". If you haven't jetted for the Super Trapp, then the jets from the 350X carb won't work. The stock sized main jet (maybe the pilot as well) won't be big enough. Since you mention that using the choke doesn't change the way that it runs when warm, it does sound like you need to go bigger on the main. You will need to experiment with jet sizes.

[oldskool83]

Your gonna need to jet it. Buy bigger slow gets and a range of mains....i put on on a mild build 300x motor which i had in my 350x and I needed a 42 pilot and a 148 main. Thats just for my motor, not yours. $100 of brass jets, after noon and a 6 pack. It will be dialed in.