Hi John and Rene,
The fuel system on your chainsaw has a filtered inlet that goes to the input tube of the carburetor. The other hose on the carb is the priming hose. It runs from the carb outlet to the input, or suction side, of the primer bulb. The last line runs from the output side of the primer bulb back to the fuel tank. It is the return line.
When you prime your saw the primer pulls filtered fuel into the carb, to the primer bulb and then returns excess back to the tank. To find the suction side of the primer bulb, attach a piece of fuel line to one side of the primer. Now put the line in a small container of fuel. If you see bubbles when you press the bulb, the hose is hooked to the outlet side of the primer. If it sucks fuel into the bulb then you have found the suction side.
Identifying the input and output side of a carb that has a remote priming assembly can be very difficult and there is no rule that applies in every case. Usually you just need to use trial and error on those connections. If you have hooked everything up so you are pulling fuel through the carb, not pushing it into the carb, and your saw won't fire, you should just need to swap the lines on the carb and then it should run fine. The important thing is that you have the priming lines setup to pull fuel through the carb.
I hope this helps!
-UtahAV
-Mark