Any weed-eater guru's out there?

I had a similar problem with a weed eater but I dont remember what brand. I couldn't make it run so I went out and bought a new one.
2 days later friend came by who just happens to work for a Kabota Tractor / lawn and garden. In about 3 minutes time he had removed what resembles a catalytic converter behind the muffler. It started on the 2nd pull and ran like new.
I should add that i had half assed mixed the fuel/oil ratio in that units history. I learned my lesson. I now mix fuel and oil like a chemist. LOL Today the not so new Cub Cadet still runs fine.