I have a ST145 homelite w/w that has two lines from the carb going into the fuel tank, one for filtered fuel the other for what? Does it make any difference how long the mystery line is. Both lines were just hanging from the carb and the rest was in tank in pieces, any help would be appreciated. Thanks :)

The 2nd line is just a fuel return line. Doesn't matter how long it is as long as it doesn't fall out of the tank ;)

Thanks for the info, when I use the primer bulb it is pressurizing the fuel tank, something just doesn't seem right. I have noticed that there is a fuel pump at the top of the Walbro carb, just how does this fuel system work. Thanks

The primer should not pressurize the fuel tank... sounds like the two primer lines are reversed. Primer (or better to be called "purge" bulb) can work in two different ways.

One is the primer sucks from the tank and pushes fuel into the inlet side of the carb. The 2nd line then returns fuel from the carb (pump side) into the tank.

Second is the inlet side of the carb is attached directly to the tank. The primer attaches to the pump side and sucks fuel through the carb and back to the tank.

Right off hand I am not sure which system Homelite uses. I'd have to wait until I got back to work and take look at one.

Thanks for the reply, I may have misspoke on the fuel the fuel pump at the top, there is a valve plate with 2 tabs over the orvices but no diaphram. Here is more infor off the unit.
ST-145 15" cut UT# 20556A S/N HL3160111 Homelite String Trimmer
The carb is a Walbro not much for ID #'s some small faint #'s stamped into it, they must go by just looks to identify it.

If you go at http://www3.sears.com and search on ST-145 and you will find some exploded views of your trimmer. You can see how the fuel lines go into the tank. The carb isn't clear in the picture but it's an easy trial and error process on hooking the lines to the carb... it's either right or it isn't.

If it's right, you can prime the carb.... if not it won't prime.