Yamaha 225 SHO

[Lookout]

I know the dealer said this engine was designed to run on 10% ethanol. However i have been running non ethanol and only treating with ring free. Is this problematic?

[K.D.]

Absolutely not. It CAN run on ethanol if that’s all that’s available but if you have non-ethanol in your area all the better.

[waknbass]

I believe your better off running 87/88 with ethanol and treating for it than running 91/93 non ethanol. The higher the octane the cooler it burns which creates more carbon build up. Carbon is a bigger concern for me than ethanol.

[MCIPinkie]

I would recommend you read your Owner's manual and ignore everything else you hear, particularly anything you might see on the Internet.

[utinator]

I don't think any outboard was "designed" to run on 10% Ethanol. They may be able to *tolerate* up to 10% Ethanol, but non-Ethanol gas is better. Also, use whatever octane your owner's manual says.