New Ethanol free stations!

[GeoFisher]

just looked online and Mercury, Yamaha, and Evinrude all state to use 87 octane for the new motors with the exception of a few motor types.. I know my Pro XS merc takes 87. So like most people have said check that owners manual or you could inadvertantly cause severe internal damage to your motor....

Can we say BLOWN power head.........

90 Octane in any of the newer motors......Opti, ProXS, Yama, Rude.......pass say 2005 or so generate TOO much heat and will pop them like a tin can.....

BOOM goes the powerhead.

Later,

geo

[Embrey]

Can we say BLOWN power head.........

90 Octane in any of the newer motors......Opti, ProXS, Yama, Rude.......pass say 2005 or so generate TOO much heat and will pop them like a tin can.....

BOOM goes the powerhead.

Later,

geo

90 wont hurt it, but theres no benefit to it either. actually it may lose a little power. probably not enough to notice though.90 is just more resistant to burning that 87.

[GeoFisher]

90 wont hurt it, but theres no benefit to it either. actually it may lose a little power. probably not enough to notice though.90 is just more resistant to burning that 87.

Well, I'm not running it..........of course, I know someone who can help me rebuild that mother when I DO blow it

[semi75]

90 wont hurt it, but theres no benefit to it either. actually it may lose a little power. probably not enough to notice though.90 is just more resistant to burning that 87.

From everything I've read that is exactly right, the higher octane burns slower, Not hotter. One of the side effects of using higher octane in an engine not rated for it is carbon build up. That is a pretty big difference than what was stated earlier in the thread.

[bg64vw]

90 wont hurt it, but theres no benefit to it either. actually it may lose a little power. probably not enough to notice though.90 is just more resistant to burning that 87.

I should have checked back on this thread. He's right you can go up in octane within reason but its not recommended that you go down. So if your motor says 87 you can burn mid and high grade. Some boat owners use 89 octane instead of 87 because they say the octane rating falls when the fuel sits but I don't know if thats true. The higher the octane the slower it is to detonate. That's why drag racers use 100+ octane fuel in their high compression motors. If they used regular pump fuel that would blow their motors apart.