i recently just got an '86 gs450 out of a police auction. the problem i'm having is i cant figure out which tubes are the vacuum tubes on the carburetor. there is one tube coming out of each carb but from different spots and there is only room for one on the petcock. one of the tubes is right before the butterfly valve and the other one comes out somewhere else after it. the tube that comes before the butterfly vavle is only available on the one carb. my guess would be that it is the other tube but i cant figure out how to hook both of them up to the petcock. any suggestions?