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.
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 (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.
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.
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.
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 : )
See my reply #26 on this thread: http://www.fjowners.com/index.php?topic=19232.msg195814#msg195814 (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".
(https://cdn.partzilla.com/MTE/d/2/MjE2NDQyNQ-2deb653f.png)
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
Nice find Pat. Pretty sure those were the carbs I was thinking of - so they were CV's