decided to take the plunge and buy some kiehin fcr carbs for my race bike.

what is standard carb size is it 36mm?

will i want 37 or 38mm carbs?

i have my eye in some 38mm carbs but worried they will be too big

the ad says they are kiehin FCR 41 sleeved to 38mm, will these work?

 

I'm no expert by any means, but there is not alot of difference between F2's and F3's and in the F2 section on the site there is a thread about 637 engine build. And someone mentioned "Two Brothers did a build back in 91 in an old Cycle World magazine", I found it on ebay and bought it. They said with boring 1mm, more compression, better cams, lightened crank, some head porting, etc, they recommended 33mm Keihn flatslides. I would think to reap the benefit of the carbs your looking at you would also need all or most of the other stuff to go with it......cams,pistons,porting,etc. Just my 2 cents.

 

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thats an f3 with very few engine modifications although a bigger air box i may ask the firm about getting a one off never hurt to ask. 37mm maybe i should run 36mm fcr carbs i know of a cb600 hornet with 35mm fcr carbs

 

Well that was interesting.

 

Let us know if this works, would be interesting to see what the possibilities might bring. Do a pic/write up and if even possible dyno charts before and after. May be worthwhile doing. Keep us posted.