Re: 250 hpdi yamaha 2003
Your buddy is racist! All engines die from ethanol after some time. Opti's have their fair share of problem (expensive ones) just as Yammies do. Just fix it as it breaks or get new motors now if you want less problems.
Consider taking the motors to a good Yamaha dealer and have them go through EVERYTHING. It will be expensive, but worth it. They will know what to look for, what to replace and what to service. There are a number of sensors that can be looked at with their computer and if any are on their way out, a good mechanic will catch it.