by Fulltilt » Fri Jan 27, 2017 12:20 pm
According to my Stihl service manual, the short spigot on the primer ( stihl calls it the "manual fuel pump" ) is connected to the hose coming from the carb.( suction)
The long spigot connects to the hose going to the tank. ( return)
Which, FYI, is pretty much standard for most remote primer bulb hookups, regardless of brand, as they pretty much all have a short and long spigot.
An easy test is to depress the bulb, and put your finger over the short spigot, the bulb should stay reasonably collapsed if it's good.
A mind is a terrible thing to waste...