Pappy once again hit the nail on the head. They're only as good as the person who maintains it.
One thing that I think is beneficial is a new style EPA compliant fuel tank. They are sealed; no vent. At first I hated them with a passion. Couple years ago I did an experiment to see what their purpose it. I took 2 one quart mason jars and filled them both halfway with gasoline (no oil, no ethanol just gas). Verified ethanol content with test strip to be lower than 1%; as the place that sells us our fuel advertises "no ethanol". One jar I put the lid on. The other I left the lid off. In 2 hours time, the lidless (vented) jar lost about 40% of it's fuel volume while the non-vented jar didn't lose any. But the lid was tight; when I removed it, it had some pressure. Also, in the vented jar, I could see WATER in the bottom of the jar. How on earth? It didn't have water in it when I poured it in? Well....fuel (along with other liquids) will lose heat as it evaporates; I noticed that the jar was cold to the touch. On a humid day like it was that day, the fuel jar cooled to the point where moisture would condense in the fuel. The fuel actually got cloudy because of the condensing moisture. By the next morning, about 60% of the fuel was gone and there was a few ounces of water in the bottom. Let it sit another day and nothing more had happened; same volume, same water in the bottom.
Point being, a vented fuel tank can do the same thing; allows fuel to evaporate, which causes evaporative cooling, which draws in condenation. I could see with a 6 gallon fuel tank (as opposed to 1 quart jar) it could draw in a lot of moisture. It was at that point that I went ahead and bought a new 3 gallon EPA compliant (low permeation) fuel tank. $65 but fuel doesn't evaporate. Plus since the old 3 gal tank was basically 4 weeks old, I put it on CL and sold it for $30 cash and recovered some of what the new one cost. Lot of people still hate the new tanks and I understand why; but there is a purpose to them.
Verified that purpose with a factory Yamaha rep.