Tunning weber carbs (air bypass screws)

[Hilario]

Hi
i have a question about the tunning of weber and dellorto carbs, what is the function of the air bypass screws? it's necessary to tune correctly the carbs? that screws are always screwed tight till the end.

thanks very much

[33gold]

The air bypass can be used to syncronise barrels, if you have one barrel on a carb that is a bit high in drawing air you can use the by pass valves to even them out. If it's really out though you have other problems such as a bent butterfly shaft etc. Most people leave the air bypass alone.

[Hilario]

Thanks, I have one bypass screw damaged and I can’t move it, it's still possible synchronize the 4 barrels, the other 3 equal to that one whit the screw damaged?

thanks very much