Sounds like bad gas which fouled the carb. That is usually a rebuild or at least a tear down and soak and ream out all orifices. If it's running, even poorly, put SeaFoam or equivalent in the gas and it might get some of the crud and varnish out of the carb.

Did you put Stabil or other preservative in the gas? Ethanol in new gas and small engines is a very evil match

How old is the trimmer"

I would check the air filters and check the muffler to insure that you don't have a partial blockage.

Do you have the plugs set to the right gap?

Are there any places the spark plug wire is touching the engine, ie burned partially through.

Has the gas line been pulled out, so it in not always in the gas?

Is the gas line crimped?

Is the filter on the gas line clear, or is it partially blocked?

exmar...it could be fouled gas but that is one thing I have always done...used the gas immediately or added a stabilizer if it sits at all. It ran flawlessly last fall before I emptied it for the winter. Before I started using it, I can't say a stabilizer was always added but it ran well for me either way. The biggest problem I had was line changes with the poorly designed head.

krnuttle...I can't exactly say how old the trimmer is. Others in my family used it before me. Maybe 4-5 years? It is a model (still available I think) that accepts attachments hence why I would like to see it working again. What tool would I need to be sure the plug is set to the right gap? I will check the other things when I get a chance.

Thank you both for the help. It is much appreciated!

So my mistake may have been sourcing out the trimmer to be serviced. I hastily did it because I wasn't feeling well and I don't really have a proper work area. Since the person I found did a great job with the mower, I didn't think twice. Well, the mower came back great but the trimmer came back looking essentially untouched. If it was touched, whatever was done didn't help. I won't make that mistake again.

As far as what was actually wrong? My uncle did the work because he knows these things and I am still weeks away from a work area---being trimming season, I can't wait. Plus, what might take me a few hours, he finished in no time. First, the plug needed replaced. The air filter was also soaked in oil(far too wet to function properly). I don't know if this can happen in a sitting unit? The idling also needed a slight adjustment. If nothing else, I learned my instincts when it comes to engines are better than I believe.