what is the problem?

You ask the question. I will give you my honest answer.

Ryobi

Those things like TroyBilt, WeedEater, Poulan trimmers are all what I call two year machines. For that is about all of the use you are going to get out of one.

Not enough gas getting to the carburetor.
I would try to open the high speed jet first.
Many weed eaters develop problems from the alcohol in the gas. This usually clogs the internal screen.
This is a easy rebuild.

Same Problem with another Ryobi Model. I run on half choke and if it ever gets bumped to full choke, the trimmer dies and then takes 1 minutes to cool off and then restart. Been mowing since 2001 with this so called "problem" but haven't found a weed eater that can take the commercial beating that we put on these (own lawncare company for boiselawncare.net) day in and day out. My current weed eater is going strong at 3+ years, but this is only my second weed eater since 01. Both Ryobi. Not bad if you ask me!

You can get these replacement carburetors on Ebay. They are made by Ruiing.

I have installed 5 of them and I did not even have to adjust the jets. They run on the first or second pull cold.

The one I purchased was the

Ryobi 30CC 26CC RY30240 RY30260 RY30530 RY30550 RY30570 BRUSH CUTTER CARBURETOR. On a winning bid $7.

There are 2 types one with and one without the auto choke kick off. Get the auto choke kick off.