Re: Yamaha 90 Four Stoke - any known problems?
They are an overall excellent motor. However, there was an issue with the older models that allowed gas to get into the crankcase oil. I believe for 2003 they had it solved with new thermostats and possibly running a hotter plug.<br /><br />People who had these engines basically had to run their engines hard for a couple hours to make sure the rings would seat in the cylinders. I have the F80 and didn't hear of any similar problems and has been an awesome engine.
