Hi do the carbs off any of the other Suzuki 250cc fours fit the 250 Across? One of the carbs off my bike has had the 2 recessed jets damaged (by a previous owner), presumably whilst trying to remove them. One of the jets has what looks like a broken drill bit lodged in it. Thanks Garry.
I would look for a set of carburetors that has 4 at ~18.364mm throat diameter thereabouts according to my calculations, with the same mounting centers as yours. You also need to consider the same throttle and choke control systems so as to keep modification to a minimum I guess. I am currently experimenting with a similar arrangement but not on a 250 Suzuki (a 750 GSXR). As long as you can replicate the same fuel mixture you should get an equivalent or better result. Others may have a better solution but I like to experiment.