--Has anyone figured out the 350X with 400EX carb yet???

[TatTooL23]

I am wondering if anyone has worked out all the kinks yet with running a 400EX carb on a 350X? I know the bore is bigger so that helps out but I had read that the accelerator pump feeds a little too much fuel into the motor. So can u just adjust the accelerator pump? Or can u just not hook up that part? And what jets might be needed, or can u run the stock jets for a 400ex that r already in the carb?? I would love to do this change just wanna make sure it actually will help. If anyone has more info on this let me know. Thanks.

[floydechoes2000]

I put one on my 86 350X recently. It's a fairly easy swap, you just have to work a little to get the rubber intake ducts over the carb. I used the stock 400EX main jet and the pilot jet from my X's original carb and it works great on my stock engine. The first time I rode it after the swap I found out it wheelied way easier when I ended up in the bushes in my back yard lol. It seems to have added low end grunt and top end power, I highly recommend it!

[69-ss-396]

I'm running one on my 86. it is .20 over with a 12:1 piston and Cam.. I'm running a dg pipe with no air box and a uni filter.. I have it jetted with a 155 main and 38 pilot with 2 turns on the air fuel mixture screw. Heat the intake boot and slide the carb right in. I have found it to be easier to take the carb and intake off or install as one as it is tight between the frame and motor..

[Doppler]

I have one on my 85 and am still messing with the jetting a little. I went with a 42 pilot with the fuel screw at 2-2.5 turns out, and had to go way up on the main I'm at a 165 right now. Needle clip is in the 4th from top groove. Choke is almost useless with the 42 pilot, same with the stock carb also. Stock jets work with stock airbox and exhaust up to about 4000ft or so. If you take your airbox lid off and run a uni or similar filter and then put on an aftermarket exhaust you will need to to fatter on the jetting. Don't just mess with the pilot and main like most people, there are other phases to a carb.
Pilot, fuel screw, needle, needle clip, main, float level. That's pretty much it for these carbs, there are others that have more.

[2hundredx]

what year 400ex carbs are you using ?

[Dirtcrasher]

Everyone's situation will be different.

If you want to run a different carb, be ready to play with the jets and air screw. The float height is fixed.

If you don't have engine mods (are they listed here??) then it may run fine with a main and pilot up 1 or 2 sizes. Your letting more air in and need more fuel in too.....

If a choke is useless with a 42, it's too big.