FCR 39 or not

[Daver]

i can get my hands on a really cheap FCR 39 for my ex , anybody tried it ? is it worth it? , i have 426, 11:1, stage 2 cam ,porting ,complete dmc exhaust, no lid airbox,k&n
and a stock carb with choke removed !!
Like to have an opinion from someone who tried it. not someone who heard or saw his cousins brother bla bla bla ...
http://i91.photobucket.com/albums/k314/Daver76/100_2769.jpg

[400eXr1d3rZ]

From what I hear, it's one of the best carbs you can get for a 400ex. I say go for it.

[MO-EX-RIDER]

if its cheap....give it a try

[NacsMXer]

If you can get a good deal than go for it! I run a FCR39 on my 450 stroker and it's a beast, the throttle response is amazing....puts the stock carb to shame

[GPracer2500]

I've ridden 400exs back to back with and without an FCR.

Bike 1:
stock carb, no choke
416 10.8:1
HC stg 2
UNI with open airbox
WB e-series slipon

Bike 2:
39mm FCR
stock piston
Sparks ported head
unknown cam (pretty sure it was a Sparks)
K&N with open airbox
Sparks full exhaust
(this bike blew and was slapped together with stuff we had laying around--that's why it was running with a port job and a stock piston)

Tooling around the little dunes near our camp (Glamis) riding the quads back to back, the FCR bike felt faster. Waaayyy better throttle response--lots more snap and engine response. Once we got them out to a big hill and dragged them, it was clear the non-FCR quad was actually making more power. It won every time regardless of the rider. Paddles were identical.

I think the piston in the non-FCR bike was responsible for it's greater HP but the FCR bike had a huge advantage in throttle response. The throttle response made it feel faster even though it would loose in a drag. I'm quite sure that had we put the FCR on the 416 quad it would have enjoyed both a HP and a throttle response advantage.

[Daver]

so this 100$ would be well spend?!and you think i would feel the difference even know my stock carb had the choke removed ?! cause i just rebuilded my top end and finaly properly jetted the stock carb!!! so this mean i would have to start all over again with the jetting !!, i will think over the night !the guy whos in desperate need of money gave me untill tomorow.
is there something special to look for or ask before dealing with him , cable ? adaptor? is this a perfect fit or do i have to
modify something like the intake ?thank to everyone who replyed.

[GPracer2500]

Originally posted by Daver
so this 100$ would be well spend?!and you think i would feel the difference even know my stock carb had the choke removed ?! cause i just rebuilded my top end and finaly properly jetted the stock carb!!! so this mean i would have to start all over again with the jetting !!, i will think over the night !the guy whos in desperate need of money gave me untill tomorow.
is there something special to look for or ask before dealing with him , cable ? adaptor? is this a perfect fit or do i have to
modify something like the intake ?thank to everyone who replyed.

A $100 FCR that doesn't have any major issues is a no brainer, IMO. Even if you decide not to use it you can re-sell it. It's worth more than $100.

As far as how simple it will be to install--that depends on which FCR it is and where it came from. If it was meant for a 400EX and includes throttle cables it should be a simple bolt up. If it's from some other bike or quad then the install will be a little more involved.

[Daver]

ok thanks GPracer i`m gonna get it and try to give you feedback

[Daver]

Hey GPracer i just talked to the guy and he told me he has 2 carb for sale one from a yz246 and one from a yfz450 both are 39mm and he told me the one from the yz is a little bigger than the one from the 450
.is it still a good deal ?! some one told me that it was a little shorter than the stock 400ex carb is this true and will this be an issue ?

[Chino886]

Originally posted by Daver
Hey GPracer i just talked to the guy and he told me he has 2 carb for sale one from a yz246 and one from a yfz450 both are 39mm and he told me the one from the yz is a little bigger than the one from the 450
.is it still a good deal ?! some one told me that it was a little shorter than the stock 400ex carb is this true and will this be an issue ?

The intake boot will have to be "bored" out a bit and the shorter diaphragm will mean you will have to have the airbox moved forward just a tad. I had the YZ 426 carb on my bike and one that was meant for a 400EX on my bike. I tried the Lectron and stocker before I went with a FCR.

Definitely buy it, you will not be sorry! Best carb for the money in my opinion!