400EX carb on a 300EX? Has anyone done this?

[ThorChick]

I was wondering if anyone had ever taken a 400EX stock carb and put it on their 300EX? I was thinking about doing that sometime this month and wanted to get any advice from anyone who has done it before. I also wanted to know which jets we would have to use? We are assuming we'd have to go down jets, but aren't sure because of the mods I have on my 300.
Any info anyone can give me would be great. Thanks!

[2fastandfurious]

Tina and i have been tlaking about this alot. So far she has convinced me that it is not a good idea. For our smaller quads..(250 and 300's) it casuses more harm then good. She was not able to explain it very well to me. So i am going to call hatricks and find out the scoop. I have been wanting to do this for a longggg time. I think thought u might want to think about a 330 kit before the carb.......

[300exazzkikr]

the larger carb is only good with a worked motor for the 300.

[ThorChick]

I keep getting told different things on this. Some people say its a great mod, others say its bad. I almost just want to try it out to see how it much of an improvement it would be, if any. A 330 kit would be a good idea if I wanted to keep my 300, but I don't really want to at this point. I'm not as in love with it as I thought. I'd really like to have a Predator, but I'm gonna wait to test ride one first.

[JOEX]

If you don't plan on keeping the 300 don't put any money into it ... you'll never get it back out when you sell. This goes for any vehicle unless your "fixing" it.
Save your money for the new quad;)

JMO, Joe

[airheadedduner]

I think the 400's is a 35mm. Now there is such a thing as over carbing a motor. When you get too large a bore the motor can not produce enough vaccum to give the fuel charge sufficent velocity for good low-mid performance.

You may get better top end but most likly your low-mid will suffer so bad that it will not be worth it.


I posted this in 2fast's thread earlier, I got it out of a 2 stroke tuning book, applies to you thumper riders too.

I will put it this way.
300ex carb on your ex would be like drinking out of a straw.
400 carb would be like drinking from a toilot paper tube. Don't work so good.

:p

[330exracer122]

400 carb is a great mod i put it on my 300 u gain allot of topend and dont really lose any bottom end

[ThorChick]

330exracer122 ~ Which jet would you suggest we run on my 300 with the 400 carb considering the mods I have? A friend of ours is selling us the carb for only $40 and another friend of mine offered to do the work for free for me, thats why I don't want to pass this up if it might actually improve anything.

[330exracer122]

right now im runnin stock 400 jetting an its doin real good u'll gain allot of topend power from this an all u need is the carb an 30 mins of work an u'll be set. u dont need a 350x air boot but that will give u even more power becuase of increases airflow

[TRX_Thumper]

but the 350x air boot wont work..a 350x actually uses a carb smaller than the 300....300-32mm and 350x is 31...its hard enough to get the 400 carb in the 300 air boot would be really hard in the 350 air boot

[300extreme#8]

but would the 400 carb work good with a 330 kit