Troy Bilt TB-35 Throttle Trigger Problem

This trimmer starts and runs fine on the start throttle setting-which is pretty much maxed out.

Seems to be no problem with the engine or getting fuel to it.

As soon as the trigger throttle is used it will idle fine indefinitely but as soon as more power is asked for through the trigger it begins to run rough and dies unless brought back to idle.

I tried reaching down and repositioning the red lever near the carb and primer to "start" while running and it ran fine again on that full throttle setting.

Don't really want to be just on or off.

Machine is about 3 months old and on Lowes Protection Plan-just checking if there is something simple.

Did run some fuel system revitalizer in it-no effect because it seems to be running ok.

Thanks for any help.

Take it back.
the low speed circuit is blocked and you are starting on the high speed jets.
Unfortunately when you pull the trigger and start to spin the engine fasted, it needs both the low & high feed.
By the time it gets to WFO it is only running on the main jet so the fact that the low speed jets are not working does not matter.