Any OEM carb choices for the FJ ?

[turbocamino]

  Curious if anyone has had success fitting other ,larger, OEM type CV carbs ,,i think i read that FZ1 or maybe ZZR Kaw have been tried?  This would be for a 1300cc 150+ HP motor.

[fj1289]

I thought there was a post or two about FZ1 carbs, but can't find it now.

I did find this: http://www.fjowners.com/index.php?topic=3381.msg28526#msg28526

If you are looking for performance though, I'd really have to recommend performance carbs - the Mikuni flat slides or the Keihin FCRs.  I've run both - both make great power.   The Keihin's are amazing carbs - can be difficult to get setup, but very worth while.    You can easily adjust both air and fuel for all circuits to get them to fuel perfectly.

[turbocamino]

  Thanks for that link Chris,,it answered several questions.  I see that FZ1 carbs are 37s and the FJ's 36mm ,,may not be worth the effort?  No doubt i am leaving HP on the table without good carbs,,I have had a couple different sets of Mikuni's over the years and it always made for a jumpy ride compared to the vacuum carbs.  There was mention of zx1000 carbs ,, hoping they are at least 38mm?  thanks. 

[fj1289]

Another option - but not CV's (at least I don't so) - some GSXRs came with flat slides from the factory.   They may be a bit more well behaved - but will be very hard to find!

Sounds like you would really like the roller slides of the Keihin FCRs -  really smooth compared to the Mikuni flat slides. 

[turbocamino]

 The FCR's do seem to be a solution the more i read about them,,  big pill to swallow though @2K !  gulp.  These days all out HP is not at all why i ride.  This new engine was a fun project with minimal stress involved, Web,540 cams Andrews 1297,, and a somewhat local guy ,that did ProStock bike heads for many years ,,even a world championship to his credit,,got mine in and done in 5 weeks,,not a big valve head but the bowls and runners are a work of art to my eyes. Degreed to 106/108 (thank you Robert) ,, should be peppy : )

[Pat Conlon]

See my reply #26 on this thread: http://www.fjowners.com/index.php?topic=19232.msg195814#msg195814

I found in the UK some Mikuni 38mm CV semi flat slides off the '90-94 GSXR 750 (Mikuni BST38SS aka slingshot carbs)
The USA/JDM GSXR's used the 36mm carb, not the 38mm carb. You gotta go to the EU to find the 38's.

I don't have these installed yet, but *in theory* these have the potential to be the best of both worlds, a CV carb that compensates the fuel mixture for density altitude along with a 38mm bore for high rpm volume.
They have a unique slide design looks like this  —U— hence the nick name "slingshot".



The GSXR's rack needs to be shortened in the middle from the 77-93-77 spacing to the FJ's cylinder spacing of 77-85-77

Cheers

[fj1289]

Nice find Pat.  Pretty sure those were the carbs I was thinking of - so they were CV's