I have been having a series of problems with my 2002 Yamaha 9.9 4-stroke
outboard, mainly with blocked up carburetor jets. This season, I have had to
strip them down three times to clean the jets. I have been putting Stabil and
Mercury Quick Silver Cleaner in the gas tank, and that seemed to help for a
month, until today, while out on Lake Michigan the engine stopped running
again. I don't know if all 4-stroke engines behave like this, all Yamahas, or
just my particular engine. I expect better performance from an engine costing
over two thousand dollars.