400ex carb on a z400?

[JBENSON]

400ex carb on a z400. Has anybody ever did this? Is there any advantages?

[twincat800]

From what ive found the 400ex has a 35.5mm carb and the ltz400 has a 36mm carb so i would say no dont try it. Its possible the ex carb is better in some sort of way but probably not worth sacrificing that .5mm so stick with stock or go with a carb of a yfz450 (fcr39) or the other ones that people go with if you want to get one and get advantages... But you will need other mods to really notice the power a bigger carb offers.

[scotturban]

My older brother has 400ex carb on his 03 kfx400 with the 400ex thumb throttle, works great, more power for sure,

[twincat800]

Hmm that sounds wierd, i know the 400ex i heard has better throttle response but the ltz is supposed to be quicker. Interesting but if you have to buy a 400ex carb then my opinion is to use that money for a fcr39 from a yfz450 but im not sure it thats too big for the standard 400 bore. Let us know what you end up doing!!

[scotturban]

Our kfx400 got a 400ex carb, because our quads an 03, Remember we didnt have the option of a yfz carb then, But 400ex carbs cheap and plentiful and got us more power.

[JBENSON]

The deal is that I already have a 400ex carb. My z400 motor is a Athena 435cc with mild poting and Hot cams intake cam & stock exhaust cam, Muzzy full exhaust sytem. The quad actually runs really good now, but a little more power would be better. Just though if there was any advantages I would try it.

[twincat800]

Well in that case i strongly recommend getting the fcr39 and if you want to spend even more money for about 160 or so you can make a custom intake like mine. Back to the carb situation since you got the 400ex carb already if you got more power out of that then that would obviously the biggest bang for your buck. But i honestly think with a setup like mine you could see a gain roughly anywhere from 2-4hp in my opinion, just depends on wether you want to spend the money, i know them carbs arent too cheap. From looking on ebay for a setup like mine would cost 275 and then i have an adapter on the carb by noss machine which i dont remember exactly how much it was but around 80 maybe? Or you can just get the fcr39 and go with the 450r boot and not need the noss adapter and spend around 275. If you got the same intake as me then it looks like we would be really close as far as mods go on our quads except you would have the head port so its possible with this setup you could have over 47.00hp. So theres some options for ya.

[twincat800]

With the mods you have your engines not breathing, youve made everything larger for the air to go through but you have the stock intake setup, your flat out not getting enough air to that engine to show you what kind of potential it has. The stock 36mm carb and intake boot is holding tons of power back from what you have, i wouldnt be suprised if you got at least a 4-5 hp gain from changing the whole intake setup and i dont know how i can make that more clear to you.. The 400ex carb is another carb for a 400cc motor, not what you have, you spent the money for everything else now its time to LET THE BEAST BREATHHH!!! haha

[nastynotchback1]

A smaller carb will build more torque but lose power in the upper rpm.You are probably feeling more bottom end and midrange torque and it feels like more power but i bet it ain't

[smoke tractor1]

The ex carb will help,the stock z carb is a cv design not very good for performance,the ex is a pumper carb and having it bored out will give you a very noticable power increase!Having it bored and removing the choke then plugging the choke shaft hole is a great cheap performance mod, don't pay more than $50-$100 to have this done though.The FCR is the king of power on the z and ex for riding and racing!And you should probably use ex intake as well!