I have a 2 stroke 90hp 2000 Yamaha. I was told in passing that 93 octane ethanol free gas may be harmful/damaging to my motor. Is there any truth to this? Should I be filling up with 83 octane ethanol free instead?
If you can get 89 non-E that is your best bet just because it should be cheaper then the non-E 93. 93 non-E will not hurt you engine if that is all you can get in non-E.
Chad
Cobia 256 Express
Pulled by a Dodge Ram 3500
I do not think the 93 is harmful, it’s what I use in my oversized hand-mixer. However, I’m not sure they run as efficiently, I believe they are designed to run on standard 87 octane, but that’s hard to find in non-E.
“Sire, it belongs in truth to the Church of God, in whose name I speak, to endure blows and not to inflict them. But it will also please your Majesty to remember that she is an anvil that has worn out many hammers.”…Theodore Beza
I have a Yamaha 70 which is basically the same motor as your 90. After a $500 carb job, I have run nothing but non-E gas ever since. I recommend the same for you. Just my .02 worth.
“Apathy is the Glove in Which Evil Slips It’s Hand”.
My new 150 yamaha gets only non eth.$4.20 a gal at the marina.
Stonoman
Same here Stonoman. If I can’t find non-e then I just don’t go fishing that day. I have 2 chainsaws, 1 weedeater, and a lawnmower that all went bad over the winter from E. All had the fuel lines eat up from one summer to the next & a gunket card on teh lawnmower.
only dif i have noticed on my yammy 25 is the 89 oct non-e takes 3-4 pulls to start where when i run the 93 it usually starts on the first pull if not second!
“you win some, you lose some…but nothing beats getting some!”
Thanks all. I will just continue filling up with the 93 ethanol free…
I have a 70 HP Yamaha 4 stroke - very new. Only about 20 hours on it. I’ve been buying 87 E gas and mixing Yamalube in it (1 oz. per 10 gal). Seems to run fine and that was the dealer’s recommendation.
I have one station nearby that advertises E free gas but people around here say they aren’t real trustworthy - may not be E free.
Is there any way to tell when you see the gas is E free?
ej
that engine is designed to run on 87 octane as the MINIMUM required octane
you aren’t going to do any damage to the engine by running higher octane
higher octane is more stable when compressed
flicker
do you mean you are running yamalube RINGFREE in your fuel?
there are inexpensive test kits to test for ethanol in fuel
its a blue liquid
put a drop in a sample jar of fuel
if it dissolves and turns the fuel blue, it has alcohol in it.
if it stay together and falls to the bottom, no alcohol.
there is also a kit to determine the percentage of alcohol
It says Yamalube Ring Free Plus Additive.
I don’t know much about it (I’m new to the whole thing). The dealer said to mix it w/ E fuel.
higher octane fuel has additives in it to achieve the higher octane, these additives will usually evaporate at normal summer temperatures. In a sealed fuel system like on a car, it doesn’t make any difference, but in an open fuel system like on a boat, it goes right out the vent, especially if you let it sit. Most engine manufactures recommend a minimum octane of 85-87, but some engines require 91 minimum(250 Yamaha, 250-350 verado, 250xs mercury, F350 yamaha, …), those recommendations change from year to year as well, so check the engine you have, its should have a sticker on it somewhere(usually on the epa sticker) or check the owners manual or manufactures web site. Personally, I’d rather have fresh fuel at a lower rated octane than old fuel that has a higher posted octane
I run 93 ethanol free in mine. A few exxons carry it and the pig on folly!
i also run 93 ethanol free in mine. i get some of the best gph over any other octane level. i occasionally run 89 just depends what i am able to get.
2006 pioneer 197 SF 150 4s
Run the 93, no harm will be done and you will see increased fuel mileage. I’ve never heard about additives evaporating? I’ll dig into that.