Thanks gmax, what brand of carburetor is that? My line trimmer has a Walbro WA, and the crankcase pulsations are delivered directly to the carburetor's fuel pump compartment through an internal vent from the crankcase that is part of the carburetor body. With the WA the only hose to the tank is just used to suck fuel - there is no need to deliver air to the tank through a hose. I can't say I'm fond of the WA, but the system at least has simple plumbing. It does have a lot of mysterious lean-mixture flameouts, though, when that bloop tube in the tank cap gets stuck shut. It gets mighty hard to start, too.
