Last year, I bought one of those wheeled string-trimmer things that looks kind of like a lawn mower, but has the really heavy string where the mower blade would be. Sears Craftsman, Briggs and Stratton engine. After getting quite a bit of use, it sat for a while. Then it wouldn't start. It had usually taken one or two pulls to start, very reliable. Now, nothing. So, I put more gas in it, no dice. Now I'm thinking carburetor trouble. I have never had good luck with carbs. My feeling has been that they are inhabited by evil spirits, and I can't find the proper incantations. Cars have been fuel injected for quite a while, so I figured I didn't have to worry about it. Of course this one is plastic. I figured out how to get the float bowl off, and found that the float was moving freely, and that there was fuel in the bowl. Now what. I noticed a plastic deal in the middle of the bottom of the carb that looked like it might come out. After some judicious prying, a plastic thingy that looked like three towers came out. I discovered that there was a little brass insert that I couldn't blow through (gotta love the taste of gasoline). I showed it to my DW and asked her if she could think of anything small enough to stab into it, and sure enough, she suggested a sewing needle. Eureka. Surprisingly, I was able to re-assemble everything on the first try, and now it starts on the first pull again.