37mm FCR carb differences???

['00 WO-YA!]

Anybody wanna try their luck at explaining why a FCR37 would be better than the Keihin 38mm PE kit? I know the FCR has a pump (I think) & the PE don't but these PE carbs run pretty good w/o the pump from what I've read.

 

['00 WO-YA!]

Nobody? Well, anyone actually have an FCR?

 

[elwood]

I have a stock carb. So I can't say 1st hand but I hear mixed things about pe, some say there is a low end stubble and other say it works great. Could all be in the tuneing?

 

['00 WO-YA!]

Unfortunately most issues are, still totally interested in making an FCR work man, I just wonder how much room the 37 will leave on the table. I'm sure the 39 is too big, it would likely scream up high but be sluggish down low. The 37 I'd imagine would work ok up to a 400.

 

[beastlywarrior228]

The 39 is popular with the 400ex crowd

 

[bones]

I would have to agree with that possibility man. If I did it I'd want the twist to be a temporary solution til I could figure out a thumb setup. I'm sure some guys love it though.

just a side note but motion pro makes custom cables as well im pretty sure they could make you a cable that will work with stock thumb throttle housing or the yfz throttle housing

http://www.motionpro.com/motorcycle/custom/

 

['00 WO-YA!]

Beastly, I'm sure you're gonna go for the 39 right? Motion pro has already crossed my mind guy, I need to call or email those cats, I might try sending them a email.

 

[beastlywarrior228]

ya with my 446 but i already have a 38mm mikuni that came with it so ill see when i get it together

 

[duneracerweston]

i imagin you can make the trouttle plate on the carb work a thumb throttle if you worked it long enough

 

['00 WO-YA!]

ok, well I just emailed motion pro, hopefully I'll get a positve word back from them!

 

['00 WO-YA!]

Well, I'm a bit disappointed. I emailed motion pro several days ago & havn't gotten a response, wth??

 

[beastlywarrior228]

Ok apparently the 37mm is used on the 300 built raptors, im still lookin into it but i think you can use a yfz cable with it

 

['00 WO-YA!]

300 built? I don't understand, pardon my ignorance. What's a 300 built Raptor?

 

[beastlywarrior228]

Raptor 250 built to the legal national 300

 

['00 WO-YA!]

The FCR isn't stock tho right? The 250 is just a lil 2 valve, single cam engine too, can't imagine they'd put that carb on stock. You got links to this Beastly?

 

[beastlywarrior228]

Im still lookin into it. no it doesnt come with it stock, stock is like a 32mm but a guy i know with a 300 motor built by rage used a 37mm and this thing hauls ass

 

[beastlywarrior228]

I think one off a newer yz250f can be used with a yfz cable

 

[beastlywarrior228]

Ya know 400ex guys use the fcr 39 on stock motors with gains and dont have jetting problems so itll probably be ok for a 366 with headwork for us. Also it comes stock on atvs so the throttle wont be a problem for sure

 

['00 WO-YA!]

I wouldn't mind tryin the 39 on somethin a lil bigger than stock, we'll see what happens. Thanks for all the info!

 

[headache]

just buy a cable for a 450r or yfz. they both have fcr carbs. the threads that the cable screws into the throttle housing should be the same as the warriors