Instead of a 450R carb

[mic 902]

I tracked down a 39mm FCR Carb. Do you guys reckon it would help as much as a 450R carb on my 440?

[440_Turtle]

Thats actually a better card than the 450r carb if im not mistaken. Thats what im runnign on my bike and i love it.

[mic 902]

What improvements did you notice from stock?

[CHEVYZ]

Yup... the FCR carb is arguably the best carb you can put on your bike. The 450r is the best bang for the buck, but it is NOT the best carb on the block.

Tat being said, you should be able to notice a pretty large increase in power.

[cals400ex]

i would bet the 450r carb would flow more air. when you put a FCR 40 on a 450r, most will get NO horsepower gains out of it and sometimes it may be a 1/2 or so horsepower less. that is, unless you bore the fcr out some. however, the fcr 39 should be a direct bolt on for the 400ex. the 450r carb is not. so, i would probably get the FCR for that sake.

[CHEVYZ]

Well, considering the FCR is a straight, open flow as compared to the 450r carb which is blocked internally by componets such as the choke, I don't think that would hold true.:confused:

[FoxMxRiders]

the choke on a 450R carb is not like a 400ex one.the choke is a piston choke that doesn't take any space in the air flow!

[underpowered]

Originally posted by CHEVYZ
Well, considering the FCR is a straight, open flow as compared to the 450r carb which is blocked internally by componets such as the choke, I don't think that would hold true.:confused:

the choke on the 450r is not like teh 400ex choke. the 400ex cuts off the air to richen up teh jetting with teh choke on to help the bike start in the cold. the 450r actually feeds it more fuel instead of cutting off teh air, so there is no butterfly in teh carb bore to disrupt the airflow.

[CHEVYZ]

You both are correct. My bad... don't know where that urge of stupidity came from.

[krt400ex]

Originally posted by 440_Turtle
Thats actually a better card than the 450r carb if im not mistaken. Thats what im runnign on my bike and i love it.


x2

[bayou boy]

i run an fcr 39 but have done a few set ups with the r carb. bang for buck u cant beat the r carb but dont forget the r throttle cable and fuel hose. it is a fairly ez install for a person with average mechanical skills. i like my fcr but i got a really good deal on it if i had to buy both new i would get the r carb. if the fcr is used make sure it is set up for a 400. when i got mine it needed a rebuild i shipped it to colby at C&D he set it up...no problems she rocked out the box from him with only main jet tuning needed

[okbeast]

You would use the 450r carb over an FCR? What all has to be done to the r carb for it to be 400ex compatible.

[bayou boy]

if i had to buy both carbs new i would use the r carb.....way cheaper and works well enough to justify using it. i just wanted to take a different road than my friends did. i have been very satified with the fcr as are my friends running the r carb. dollar to dollar the r carb is a very attractive option though. to set up the r carb you need to ream out the intake tube and the air box tube to match. some people stick the air box tube in boiling water to soften up the rubber...another option. you have to cut the choke lever for clearance..look at this carefully to make sure you cut enough of the lever so it does not chaff the fuel line. make a little bracket to move the airbox 1" fwd..(r carb is shorter) i just made a lil bracket and welded it some people use a bolted version...your personal preference. the hot start is not used. there is a thread on the installation of this on a 400....do a search it has pics. it is way easier than it looks and good bang for your buck...chevyz is running one he had an edlebrock before and prefers the r carb.

[cals400ex]

i doubt you will notice a difference between the two in terms of seat of the pants power. however, the newer FCR's (FCR 40mm's) do not make any more horsepower than the stock 42mm 450r carbs. however, the thorttle response is better on the FCR so some go that route. i am happy with my 450r carb. it has more thorotte response than my 400ex carb did. i dont' think you will have a problem either way. the FCR 39/41 should bolt on easier because it is the right length so i would use that over the 450r carb. but, the price on the FCR will be more as well.

[mic 902]

OK thanks for the info guys. I might have to go with the 450r carb because the guy selling the FCR to me want $500 and i dont have that much. Everythng usually costs at least double here in Australia.