Hi is there a way to Syncro the carbs by eye... without tools ?

 

Roughly speaking yes

use a feeler guage and adjust all 4 butterfly valves to same gap between carb tube
and butterflyvalve at rest/idle

It's rough but enough to be good enough until you get a carbtune tool

 

yep Sprocks right, it does work, it is a crude way of doing it. However if you take the time it can be done fairly well. I done it prior to owning a carbtune set when I done the 750 carbs. It does take a bit of fiddling to get things right and ya got to take ya time and re-check all the way through.

To make things easier I used a cheap set of gauges I butchered so they would slide up carb throats easily. I mounted the butchered gauge to a block of wood that was cut and filed to shape so it would fit across each carb mouth in the exact same place to ensure the set up of each carb was as close as possible to each other with the gauge being positioned in same place every time in each carb throat.

Being the fussy bugger I am, I done my checks then did a final check also using a black whiteboard pen. when ya slide the gauge up, i coloured the top side of gauge with pen. as it slide under the butterfly, it just (and I mean 'just') rubbed the pen off. A bit more fine tuning, and bingo, a pretty sweet set up.

I later got a carbtune, cost effective and worth it's weight in gold. It also earns me beer every time it's lent it out to mates so is more than paying it's way