Installing 450r carb worth it? and questions

[airman88]

i was browsing threw the forums and found that a few people have the 450r carb installed on their 400ex's i was wondering how much bigger the carb is from the stock 400ex carb and if there is anything i need to do or know before installing the carb on my quad. another question is, is it worth the arverage $75 for the 450r carb of should i just save for a FCR

[2muchquad]

I would imagine the fcr is the better carb since honda went to them on the 05 and up 450rs.The 450r carb might be better than the stock 400ex carb though.Im pretty sure its bigger anyhow.;)

[airman88]

i know its bigger but by how much, and how much bigger is the 05-up than the 04's

[Wheelie]

Stock 400ex--35.5mm

FCR--39mm

04/05R--42mm

The 450R carb has been covered extensively, do a search.

[GPracer2500]

One note about carb sizing. I wouldn't bother trying to make any comparisons between carbs based on the advertized venturi size unless they are the same model carburetor. Different carbs are measured differently--a 42mm such-and-such may not actually be bigger or flow any better than a 39mm whatever. Apples and oranges.

Here is a 39mm FCR off a YFZ on the left and a 42mm 04/05 450r carb on the right. The FCR sure looks bigger to me.

http://img231.imageshack.us/img231/3055/carbs450ryfzdf6.jpg
[picture from Buck]

[400exrider707]

04/05 450Rs have a 42 kehein

06 + 450R have 40 FCRs

[CHEVYZ]

I beleive the stock carb is 38mm. The 450r carb is 42mm. These are the specs given by the companies. As said, most carbs will vary in that area anyway, not to mention there are so many more important things to consider, so do not make a decision based merely on the "size" of the carb.

As for the R carb for the EX, it is a very good upgrade. I would have to say that the FCR is probably slightly better performing on the dyno, realistically speaking, you would probably notice little to no difference on the "a*s dyno." I noticed a huge difference between the 450r carb, the Edelbrock Doug E. carb, and the stock/modified 400EX carb (stock carb). The 450r easily outperformed all of them, and "felt" the best. Definately noticable, even when compared to other aftermarket carbs. Unless you are going all out or don't want to do the slight modifications to your bike to accept the 450r carb, I would choose it over the FCR as well. That money could be better spend elsewhere IMO.

As for the mods that must be done for the EX to use the carb, that can be found by using the search button. It has been gone over quite a bit. Doesn't take very long at all.

[bansheemorphine]

check the 400ex information board there is a sticky about this it should tell you everything you need to know