Idle Mixture?

I know the convention of 2 1/2 to 3 1/2 turns out. Or set with ColorTune, but I'm trying to find out whether there was any factory recommendation about different mixtures for the different carbs.

E.g. my daughter's Ninja 250 actually recommends different settings for the two carbs in the factory manual.

I found at least one reference here saying that "... the manual clearly shows you how to re-adjust them... " (https://xjbikes.com/forums/threads/mixture-screw-setting.3042/)

I have the factory Seca 750 manual, and the Haynes 650/750 manual. The factory manual just says "Preset." The Haynes manual goes to great lengths to say that they are purposely telling you not to touch them, and that, if you do, you'll need to go to a dealer with full exhaust gas analysis equipment.

So, where's the manual that does tell you how to readjust them? More to the point that I'm interested, even from anecdotal evidence, is it typical/better to have a leaner mixture on 2/3, since they get to scavenge more fuel from neighboring carburetors by YICS?

I'm specifically interested because I'm wondering if I should play around with per-cylinder injector trim. Right now all four are getting the same fuel (within the variations of the injectors themselves).

Thanks!

 

You know a lot of you can fit fuel injection to your bike that's cool.

 

that would be the book the dealer used with the EGA that they used back in the day. i think the lack of instructions was from the EPA along with the cap on the adjustment screws.
whatever low speed mixture difference is tuned into a carb rack becomes negligible as you move away from idle.

i thought 2/3 would be richer, to run cooler, because they can't cool as well.
don't some V-twins run the back cylinder richer for cooling?

you know you want to, i think you should

 

Actually it's not uncommon to have a richer mixture on 2/3 since they receive less cooling than 1/4. The extra fuel has a cooling affect is what I understand.
The Seca Turbo is set up like this. I have a 900 Seca rack I installed a Sigma-6 Stage 3 kit and they suggested the same. Both YICS engines.

 

the 84 xj550 was jetted different on the cylinders, I have read here someplace it was for cooling or running cylinders cooler
Main FUEL Jet Size: #105 (cylinders #1 & 2)
Main FUEL Jet Size: #102.5 (cylinders #3 & 4)
Pilot FUEL Jet Size: #40
Main AIR Jet Size: #70 (non-removable, in carb throat)
Pilot AIR Jet Size: #155
AIR COMPENSATOR Jet Size: not used.
Starter FUEL Jet Size: #42.5 (non-replaceable, in float bowl)
Main jet NEEDLE ID: #4CP7-3 (cylinder #2)
Main jet NEEDLE ID: #4CP3-3 (cylinders #1, 3, and 4)

and the turbo as stated by Simmy
Years & Models: 1982-3 XJ650LJ/LK Turbo Seca North American models
Carb Manufacturer: Mikuni
Carb Series: BS30
Carb Model ID: 16G00
Main FUEL Jet Size: #127.5 (cylinders #1 & #4)
Main FUEL Jet Size: #132.5 (cylinders #2 & #3)
NOTE: the yamaha parts books reference the use of #125 main fuel jets. Original carbs that we have explored have the #127.5/#132.5 combination of jets as shown above.
Pilot FUEL Jet Size: #35

 

Thanks.

The 550 setup is really... interesting. Left side richer than right side, and a different needle for just one cylinder?