I have an ST155 trimmer. I am trying to get it running again. It wants to start, but only runs for a split second if you have choke in the correct position. There are three positions and not sure what the procedure is.I know you put it on full choke when cold, but from then on it is guesswork. To compound the problem, the air fuel valves need adjustment I believe. Do you have a complete procedure for doing all of this?
I would appreciate any help you can give.
Thank you.

Herb, July 2009

Here's how you start pesky two strokes....
Press the primer bulb a couple of times (if there is one)
Then, full throttle, full choke, pull the recoil briskly until the engine pops, then, full throttle, no choke, pull again and you're away.....usually! Set any mixture screws 1 turn out from fully in.

John, July 2009