Lack of 91 octane

[shrobs11]

Just bought a 2018 AR 195 and assumed local marina had 91 octane but only had 89. Ended up putting a 1/2 tank of 89 in to get us by for the day. Planning on getting fuel caddy or gas cans in the future. However, will running it on this cause any significant damage?

 

[jgourlie]

I think you are probably fine if you are taking it easy any hard driving would be running the risk of cause some problems

 

[d_coyne1984]

It would make me very nervous. Most modern performance auto engines will adjust for lower octane fuels, but I am not sure if the Yamaha marine motors will. You can buy octane booster from auto stores, but I don't know if adding stuff like that actually works the same was as getting formulated fuel from the manufacturer.

 

[shrobs11]

Thanks for the advice - moving forward, we are bringing 91 octane in multiple gas cans until we get our fuel caddy. My mistake for assuming marina had appropriate fuel. Good lesson for when we travel. Will certainly take it easy and slow with this 1/2 tank.

 

[biffdotorg]

Yamaha is smart about their engines that required 91 octane. They include a knock sensor from the factory. So if it detects knock it will adjust timing for lower octane fuel. It will be fine one tank at a time.

This is common with many other Yamaha engines that required 91. We have had knock sensors in our 4-stroke snowmobile engines as well since there are times we may be in remote locations where 91 is not available.

Good luck,

 

[212s]

The fuel injected engine ECU's will adjust timing as needed if you have to run lower octane. Don't worry about it...and put in 91 when you can for optimal performance.