What octane to run in a flashed 250 SHO to 300

**kk4iz** · 07-08-2019, 03:37 AM

What is the best octane gas to run in a Sho 250 flash to 300? I know that Yamaha says to run mid grade
in the SHO 250.

**clayshooter100** · 07-08-2019, 12:28 PM

Both hydrotec and Nizpro 300 tunes require 91 octane.

**Yatesville Junkie** · 07-12-2019, 07:11 PM

Been running 89 with 0 issues.

**yam911** · 07-13-2019, 07:59 PM

Why pay money for a flash to up the HP and then use a grade of gasoline that won't let the motor produce rated HP?

**THOEFT** · 07-14-2019, 07:15 AM

Shouldn’t you be able to run the recommended grade of gas that Yamaha says to run in a stock 300? Seeing only difference is the flash?

**bgibson** · 07-15-2019, 09:46 AM

This is an interesting conversation. I have a flashed SHO 250 and run 89. I wonder if going to 93 is beneficial? Anyone have input?

**walnutshoe** · 07-16-2019, 04:52 AM

I prefer the 93 non ethy in mine.

**kk4iz** · 07-16-2019, 07:57 PM

Has anyone used an octane booster with mid grade?? Amsoil has one

**yam911** · 07-25-2019, 02:37 PM

Originally Posted by bgibson

This is an interesting conversation. I have a flashed SHO 250 and run 89. I wonder if going to 93 is beneficial? Anyone have input?

It is similar to an insurance policy. Only beneficial when it is needed.

**kk4iz** · 07-27-2019, 12:37 PM

Originally Posted by kk4iz

Has anyone used an octane booster with mid grade?? Amsoil has one

well am I going to be the guinea pig on this one???

Thread: What octane to run in a flashed 250 SHO to 300