On Fri, 03 Jul 2015 20:07:42 -0600, Tony Hwang
wrote:

wrote:
I have a 2-cycle trimmer that was working just fine. Then during it's last use the speed began declining while in full throttle mode until it finally died. I changed the spark plug and now it only runs with the choke closed. If I try to open the choke or let off the throttle the engine dies. Any suggestions?

I don't know how old it is but exhaust port maybe plugged up with
carbon/dirt.
Just remove muffler and look, see.
Carburetor deposits and vacuum leaks are much more likely on today's
2 strokes since most run on a weak oil mixture, using low ash
clean-burning (relatively) oil - and ethanol gasoline. This adds up to
low exhaust deposits, and all kinds of sneaky stuff clogging up fuel
systems and deteriorating gaskets etc.