450r carb on 400ex

[djwilliams0822]

I am looking at what type of 450rthe carb to get on the 400. I've heard to get an 06 or better but what is the difference between the other models? What is FCR? I have a 440 it has stock exhaust do you think it would benefit me to get a 450r carb wth stock exhaust?

[rooster300ex]

U can find many topics on this. Do a search while u wait for replys.

[DirtyBirdRacing]

Why do you still have the stock pipe on a 440 if you dont mind me asking??

[djwilliams0822]

Haha I bought it used and I guess the guy I bought it from took off the aftermarket exhaust and put stock back on

[atvrider13]

04 05 fits better, 06 and newer fits like crap but will give better performance than the 04 05. The huge throttle mechanism is too big on them. If you can find one from a dirt bike it is smaller

[djwilliams0822]

I do mostly trail riding, should I go with the 05? Is there any difference between the old and new besides the throttle?

[ish416]

The FCR carbs are better than the piston valve carbs from the EX and 04-05 450R. They are more expensive, require some modding and will not bolt straight up.

Don't expect a huge performance increase going with an FCR over an 04-05 carb. The FCR's are all about throttle response.

I would suggest getting a slip-on to allow your quad to exhale those exhaust gasses before a carb. Otherwise I think you will just be wasting your money.

[djwilliams0822]

Thanks are the T-4 slip ons good? Is it ok to run stock headers?

[ish416]

The stock header is actually very good for a factory piece.

The T-4s are good. Really anything should help open it up. There are many people who say get exhaust A or company B is crap.

In all honesty, there will not be more than a few hp difference between the best full exhaust setup and the stock exhaust on a stock motor. Once you get into a bigger bore/higher compression is where the exhaust will really start to become important.

I would just go with whatever slip-on you think looks/sounds good to you and that is within your budget. They will all perform within a few hp of each other.

Pro-Circuit/FMF/HMF/Motoworks are all excellent slip-ons.

[DirtyBirdRacing]

I would look for a slip on, Exhaust system before a carb as well People have also told me that the stock headers are pretty good but you can make them better by grinding the header welds down (on the inside of the pipe where it bolts to the motor) And theres a guy on on here ( ZRPILOT (http://www.exriders.com/vbb/showthread.php?s=&threadid=473931) ) that sells an adapter for the 450R carbs it makes it easyier to bolt up to the 400s I like many members on here have picked one of them up from him hes a great guy to do buisness with.450R carb Install With Adapter (http://www.exriders.com/vbb/showthread.php?s=&threadid=314423&perpage=10&highlight=450r carb adapter&pagenumber=1)

[jkosakowski]

Does anyone have any pics of grinding the welds down the stock header ?

[DirtyBirdRacing]

Originally posted by jkosakowski
Does anyone have any pics of grinding the welds down the stock header ?
not sure if you can see it very good but here you go
http://www.exriders.com/vbb/showthread.php?s=&threadid=441295&highlight=grinding+header

[Thumpin440ex]

Does anybody have actual dyno's of the FCR vs the 04-05 carb??


John

[JOHNDOE83]

For sure, the 05 carb would dyno higher HP then a fcr.

Its a 42mm .

If you dont wanna use the adapter, you could also get a fitting from home depot in the plumbing section that makes it work with no mods.