I have a 1997 Yamaha 25 HP (MSHV) outboard. I've owned it a few years, but have never been able to get a satisfactory idle. In fact, it's just been a "cantankurous" SOB since I got it (probably the reason the previous owner sold it). Anyway, I've been through the carb (it only has one) several times, soaked it, poked it, sprayed it and blown it... I've also gone through and cleaned the fuel pump and filter, replaced spark plugs and endlessly tweaked the air mixture screw. It also has a clean tank and hose filled with fresh ethanol free marine fuel. Bottom line... I'm stumped and really sick of fighting this beast. Any suggestions?