[Veselin Kolev]

Sounds like you have a dirty carb. If you can take off the carp, just clean it up, put it back on. Wonders can be done by cleaning carbs... Using a carb cleaner will help, but if the clog is in the fuel lines in the carb (sometimes happens) it won't help too much. Just take it off and check it out.

Another thing that prolly isnt the main cause but will help: check out the air filter. If you flip a lawnmower over, it usually leaks oil out the air filter and cloggs it, depending on the design. If it is dirty, just leave it off and try to run it, make sure your not anywhere where it can suck up leaves or anything.

Hope that helps.