I have a 2 year old Craftsman string trimmer (Model # 316.791810). After pulling it out of the garage for the winter it would not start so I rebuilt the carb and it worked great for about a month. Then it started to idle very hard and finally would shut off where I could not start it again. I finally got it to start and run anywhere from 2 seconds to 1 min. but it runs rough and will not keep going. I have replaced the spark plug, recleaned the carb, re-adjusted the carb needle, checked the fuel lines, adjusted the idle screw and the carb screws, cleaned the air filter, cleaned the muffler plate, and this thing still won't run! I don't understand, it was running great and just died! Please help...

You mentioned many appropriate measure except buying fresh gas. 2 cycle engine are temermental little ctitters and like fresh gas with the proper mix. Because you cleaned the carb does not insure you cleared the problem. Dump all your fuel and add 4 oz of SeaFoam or other good carb cleaner to the tank. Pump the primer bulb 20-30x and then rest, 20-30 more pumps and then pump this cleaner by inverting the unit, pump the primer while it is up side down, refill with freshed mixed fuel.

OK, I put in brand new fresh fuel ( on a side note I had to purchase one of those new echo gas cans because those are the only ones you can buy in Kansas now... pieces of junk) still didn't work. So I decided to try the seafoam method mentioned and it didn't work either. I then took the carb apart and soaked it in the seafoam for a couple of hours. Still didn't work so I put some seafoam in with a little bit of the new fresh fuel. Still didn't work... I have no clue but for some reason it starts on every pull but only runs for about 5 seconds... it wants to run so bad but just won't. Any more ideas??

Thanks

Had to laugh at myself and my typos on the earlier post. I have done the same thing to a few carbs and still had no luck. Maybe we will get a carb person to tell us both how to find that last little inlet clogged with junk. I cleaned a carb twice and then rebuilt it, ended up buying a new carb for a tractor and that carb allowed the engine to start with no new tuning at all, right out of the box it started.

When you were cleaning out the carb did you press down on the little tab in the carb if not you need to clean it again except when you are spraying cleaner and blowing air in the holes remember to press down on the little tab is on the bottom side of the carb