My Stihl weedeater is the worst piece of power equipment that ai have ever owned. Never seen a small engine that floods so easily. I have an old Weedeater brand that I paid $40.00 for, many years ago, that runs better.
Sounds like it needs a good carb cleaning
The Stihl I have been using for the last 6 years is the same way. Its just the nature of the beast with some of them. With mine, you put the choke on and pull the rope till it sputters.....usually two or three times. If you pull the rope again without taking the choke off it will flood. When I first got the thing I flooded it so bad the little air filter was soaked with gas because my previous one would start with the choke on.......I was ready to wrap it around a tree until I saw what was happening. So its pull the rope two or three times till it sputters, take choke off, pull two or three more times and it fires up.
Can't remember the number of mine but at the time I bought, it was the smallest Kombi motor they had. I had an FS-250 (a hoss) which subsequently got stolen and I figured I would wear out the little one before I got another. Haven't worn it out yet and I work it pretty hard. Its all you need to cut with a string or the plastic cutters, but its not a "brush cutter".
I did allow the carb on mine to gunk up....totally my fault for letting it set up over winter with ethanol gas in it and no stabilizer. I bought another carb from the Stihl place for about 30 some odd dollars and installed it myself.
Oh, almost forgot. Whichever brand you get, consider one with the handlebar set up. Its a lot easier on your back.