Before going into storage for 2 years, I had a new cooling impeller put in our Yamaha 8hp 2-cycle outboard and a thorough fresh water flushing of the engine. When we went to put the engine back in service, it started up after a few dozen pulls of the cord but, I couldnt get it to run for more than 30seconds.
My first action was to thoroughly clean the carburetor of any deposits resulting from ethenol gas. But that was not the issue. My next thought was a defective fuel pump but, I decided it was just as easy to order a new carburetor (including new fuel pump) rather than trying out piecemeal solutions. Slapped in the new carb and the engine fired up on the first pull and runs like a champ. That's a great thing because you can't buy 2-cycle engines like this in USA anymore. Only 4-cycles are sold which weigh significantly more (and more than I can comfortably lift).