Yamaha SHO octane rating

[bigfishtx]

Has anyone noticed any reduced performance when using 87 octane fuel in these engines.

[Jkmoore03]

All I’ve ever run in my 200 SHO is 87 and it works as advertised.

[carolina o4]

I started using 89 octane on my 2020 250 sho but my last three trips I started using ethanol free gas from bucces which is 92 octane boat starts right up and runs like a champ but don't really know if the higher octane is recommended or not

[fisheye48]

I dont know of any performance issues but a very good yamaha tech told me to run 89, 93, or ethanol free with ring free in it and enjoy.

[Tejas Trucha]

It works just fine on 87. I’ve done it for years in matagorda for 6 months out of the year. I put 89 when my SHO is in Galveston. 400 hours on this regimen. All good.


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[Sgrem]

I use the cheapest 87 I can find....cuz I cant find cheap 85....
The engine is designed for it. Higher octane is a waste of money and results in zero gain. In fact higher octane than the engine was designed for can result in more carbon deposits plugging fuel filters and pumps.

[Davidsel47]

I used to run high octane all the time. I have been through dozens of 87 over the last 6 months and have seen no differences in performance.

[Bird]

The engine owner's manual will state what the engine is designed to run on. The last 3 outboards I've had all said to run 87 octane in them.

[bigfishtx]

Sho says to use 89 octane. That is why I asked. I filled up with 87 and trying to prop boat right so wondering how much the 87 octane is affecting Max rpms

[Capt_Gilligan]

The ECU will pull timing to compensate for the lower octane as it sees it in the system. The only engines I have seen a noticeable difference between 87 and higher octane fuels is the supercharged ones. They pull a lot of timing and boost to prevent detonation. As long as you don’t run E85, you’ll be fine.