41mm Carb Questions

[Turbophein]

are all these 41mm fcr's the same? can i just swap the intake housing and jetting for the drz and swap it in? i can get a fcr 41mm from a buddy that had it on a xr650. right now i have a 39mm FCR.

thanks

[Smias]

If it has a removable air bell intake for the air box it will bolt on .

Is it a fcr or a fcrMX ?

[Turbophein]

If it has a removable air bell intake for the air box it will bolt on .

Is it a fcr or a fcrMX ?

it does have the removable air bell yes.

i think its just a fcr 41mm... the MX has the black plastic throttle cable housing correct?

[Smias]

The fcrMX looks like the one in the left and the fcr looks like the right

The one in the middle is a real nice chick !

[f2dog]

the 39 and 41 are the same ,only difference is the 2mm bigger outlet .

All the parts are interchangable

[Wayward Son]

not all the same.

[Turbophein]

edit'd

Edited March 22, 2010 by Turbophein

[f2dog]

it looks like this

It's a flat side fcr ,same type as on the e-model.

Jets and needles fits from the 39 to the 41mm

[blt]

The correct fcr41mm is good for bored & stroked motors only. You wont see any improvements on a stock displacement motor..might even lose some bottom end response.

[Turbophein]

It's a flat side fcr ,same type as on the e-model.

Jets and needles fits from the 39 to the 41mm

so this will work for me then. great

[f2dog]

so this will work for me then. great

Depends of which mods you have done to the engine.

If you don't have a big bore / stroker and ported cylinder head , your bike will be worse than with the 39mm..

[restosud]

yours is a slant body fcr.looks like it has removable spigot(unscrews) and intake bell.came from sudco and is the performance offhighway model.

looks like it'll bolt right on you drz.

fine carb you got yourself.

[MutualBill]

Can't give you anymore advice until we see the rest of the chic. LOL

[William1]

I assume, you have a big bore, stroker, RHC 187 cams and a SSW-MRD or Yosh Ti exhaust already. If not, the 41 is a mistake as it is too big. I further arrume you are riding SM and not dirt as the larger carb will kill your low end.

Bigger is not always better.

[Turbophein]

thanks for the reply guys, no i will not be running this carb yet, but i also don't want to buy it if it didn't fit. i have another buddy who wants my fcr39 so it will be a pretty much even swap the 39 for the 41. i started another thread asking what my next mod should be, asking whether i should do a BB or stroker. i am also porting & polishing my head so this carb will come into play real soon.

here is the link https://www.thumpertalk.com/forum/showthread.php?t=887916

also here is my build thread for everything i did.

https://www.thumpertalk.com/forum/showthread.php?t=821079

[mickeydee]

you will gain a little top end power with the 41 as long as you at least do a BB,cams,mrd/ssw pipe but you will loose bottom end.the 39 works better for most aplications.if you plan on doing the full stroker,BB and the rest of the go fast stuff then the 41 will work better.if your riding dirt, stay with the 39 regardless of what your doing but if doing supermoto then go with the 41

[Turbophein]

you will gain a little top end power with the 41 as long as you at least do a BB,cams,mrd/ssw pipe but you will loose bottom end.the 39 works better for most aplications.if you plan on doing the full stroker,BB and the rest of the go fast stuff then the 41 will work better.if your riding dirt, stay with the 39 regardless of what your doing but if doing supermoto then go with the 41

i have this now:

FCR 39mm Older Style Slant Body (eddie's jetting specs)

Yoshimura Cams

E model Airbox, intake manifold, & CDI

K&N Filter

Yoshimura Exhaust (older dirt model with a Fat Header)

MCCT

Vortex rear alum sprocket

and a bunch of "no go fast" parts and some weight savings

if i buy a BB, will my fcr39 still work for me with my current mods? but i know i want to stroke it eventually... thats why i figured i would go with the 41mm and a BB for right now and maybe the stroker next winter.

[blt]

Sm or Dirt riding?

[Turbophein]

Sm or Dirt riding?

Sorry its a SM, i posted my build link...

[Redrodent]

Your cams are a little light in the pants for a 41. I have a 439, yosh Ti, with RHC cams and 13:1 comp. The 39 worked better, even pulled better on top, right up until I changed the cams.