Time to get this straight!

[96FMF300EX]

Ive read a lot of posts on here about changing from your stock 300EX carb to a stock 400EX carb. Ive heard that they are great for top end and you dont loose a lot of low end. And ive heard of over carbing the motor or whatever you call it. The stock 300EX carb is 32 and the 400EX is 35.5mm. Thats about a 3.5mm difference. So can you please tell me what it actually does i want to hear both sides really. cause i have a 400EX carb and i want to know if its a good idea to put it on or. Mine runs pretty good and want to know what will happen if i put this on.

Thanks!

[Sparks425Ex]

Well put it this way. Stock 400Ex carb is 35.5mm and Most guys gp up to 39mm or 41mm. That is alot bigger diff. than from 300Ex to 400Ex. You will deff get some gains all over. You aren't gonna be losing power anywhere. But you mainly gain alot on top.

If ya already have the carb then put it on. It not gonna hurt nuttin. Try it out and see how ya like it. That is the only way to truly find out.

[96FMF300EX]

So what kinda carb boot should i use on it cause the 350X one wont work.

Thanks

[300exazzkikr]

I'm pretty sure a 350x boot will work. Wiggle it on there.

[TRX_Thumper]

guys im tellin ye..ive tried this..u barely can get the 400ex carb on the 300ex air boot..ok the 300ex air boot was designed for a 32mm carb right..ok the 350x carb size is actually 31mm ....smaller than the 300...i tried an tried an couldnt get the 350x air boot on

[300exPA]

I put a stock 400 carb on my 300 after I got a 330 kit. The new carb showed big gains out of the 330kit. If you can't get the carb in teh 350x boot, boil a small pot of water, let the water cool a bit and then soak the boot in it for 10-15 sec. and then slip it over the carb, let it cool and then it will fit everytime. Be careful when jetting the new carb to make sure that it is not too lean

[wheeltrax]

isnt the 250x carb 36mm?? Wouldnt that make a slightly bigger difference then the 400ex. I know the .5 isnt gonna do much difference.

[CBW]

Originally posted by 300exPA
If you can't get the carb in teh 350x boot, boil a small pot of water, let the water cool a bit and then soak the boot in it for 10-15 sec. and then slip it over the carb, let it cool and then it will fit everytime.


exactly,,,,,,i had to do that with m310R,,,,,i know you are talking ex's here,,,,,,,,,,,,,but i had to do that to put the 38 mm on in place of the stock carb withusing the stock boot..........;)

[TRX_Thumper]

naw there never was a 250x comin stock with a 36mmm...also i think it was like in 94 or 95 that the 300ex got upgraded to a 32mm...the older ones had 30mm...and seems like some of the 250x's had 28mm...

[Burden7]

The 400ex carb will fit on the 350x intake boot. I was running one for a year on my 350x and now I have a 38mm carb fitted to a stock 350x intake boot. The boot is stretched a little, but it fits fine. Right now I have an FCR41 fitted to a stock 350x intake boot, but I had to do a little machine work to get it to fit. :D

[mod300ex]

so if i get a 400ex carb and put it on there i will gain top end speed?????

[96FMF300EX]

I put the carb on yesterday. I boiled some water and stuck the intake in and then slipped it on (piece of cake!). I went out and road it, had no trouble starting no bogging or anything. Right now im liking it but we will see. just thought you guys would like to know how it turned out thanks! Hope to have pics of my quad soon. Thanks for the help.