Bubbakat gave the best suggestion to everyone with a boat. Buy a shop manual BEFORE you need one. I work on a lot of motorcycles and they are a whole different animal but suffer from the same problem boat motors do. Lack of operation. If the motor sat for an extended period time prior to you buying it and you don't find anything out from the above I'd do four things. 1. New spark plugs 2. Add Sea Foam (Auto Zone) about twice as strong as they recommend on the can. The first thing that clogs up are the idle jets on most small engines. I've poured Sea Foam on the solid hard brown goop inside a float bowl that has sat for over 3 years and it all goes into solution. 3. Make sure you have good fuel. Tapping the choke helping tells you it's probably a fuel issue. 4. Listen to Bubbakat. I've read a bunch of his posts and if he doesn't know I think a guys in for some trouble.