I just bought a Yamaha WR500 and was wondering if pump gas would be a problem for the motor? The local marina here sells premixed, but I wasn't sure if I could mix it myself as well, didn't know if the ethanol would cause a problem.
If it's still using the oil injection system, premix will make it to rich on oil. If not, mix it at 50:1. That's prob. what the marina is mixed at. Yes you can use ethanol based fuel, but you must use a fuel additive to offset the ethanol.