2019 YZ250F Fuel Question

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2/25/2019 10:07 AM

I guess this could be a question for general fuel usage.

The 2019 YZ250F compression ratio is 13.8:1. The manual recommends to use 91 octane or higher fuel with less than 10% ethanol. I have access to 90 octane non ethanol fuel. Do you foresee any pinging or adverse effects if I run 90 octane non ethanol fuel? Should I add octane boost to get it above 91 octane? I'd much prefer to run non ethanol gas if I can, but 90 octane is the highest I can get of non ethanol.

Thanks for any help/ knowledge you can pass down!


2/25/2019 10:36 AM

Vp t4. Great consistent fuel


2/25/2019 11:50 AM

Best thing is to try it and see. Every bike is different.


2/25/2019 12:53 PM

One point of octane is within the variability of the blend. We run pump premium with ethanol and have no issues. If you were really worried, add some fuel and pull some timing out in the map.
I’ve never seen anyone that has detonated a small bore 4 stroke Yamaha.



2/25/2019 4:39 PM

Thanks for the input. Guess i'll see if I get any pinging when the time comes. As of right now, it's still got whatever the dealership filled it up with.

Sounds like 1 octane off from recommended shouldn't be a big deal, but if it is, i'll add some octane booster.

Thanks again all.


2/25/2019 6:20 PM

I'd rather run 91 ethanol than 90 non ethanol personally. The E10 fear is overblown for modern bikes and cars.