Thanks for replying. Good question about the manual. It's a Clymer. The carb has 3 hoses I can see with a diaphragm on top. There is a small aluminum Mikuni component with 3 hoses attached. It's about 2.5x1.5x.5 inches. One hose goes to the fuel petcock, 1 to what I think is the engine vacuum and the other to the carb? The fuel pump maybe?
I'll see if I can find a genuine service manual. Do you know where to find one?