I have an older OS 120 with pump, I got it from my uncle and I believe he purchased it in the late 80s or early 90s. The pump looks very different from the ones on the 120 I see on the OS website. I want to know how the fule lines are attached to the pump and how to set up the fule tank, do I need a vent tube or what. Thanks for your help.

Well,I have a 120 pumped,but probly not as old as yours. Mine has a line "in" from the tank. An line "out" to the carb. And another line not labeled that is the line that connected to the vent line of the tank.....kinda like an return line. If you could get us a picture,that would help alot.

I agree I have a Surpass 1-2 hybrid that has that same kind of pump. It has a fuel in, a return to the tank, a line to the carb and the vent from the tank goes to the atmosphere, not to the engine