400ex Carb on 300ex

[MX174]

Ive searched on this a little bit but didnt find anthing that said much about it. Is this just a bolt on thing and you get the jets right or what? Is it really worth the money or just stick with the stock 300 carb?

[Jonesy]

If you have head work, cam, big bore and pipe it would be worth putting the 400 carb on. Other than that it may not be worth your while. You have to heat the intake flange on the back of the engine and stretch it out to make it fit. The of course get the jetting right.

Jonesy

[efilnicafesin]

Actually, the intake side is the same size... it is the inlet side of the carb from the airbox that is different and needs to be heated or changed. I did it on my 250x with 12:1 and some other mods, and it made a huge difference.