Aquaman wrote:Greetings,
Has any of you heard a rumor about how added ethanol mix in the gas we pump at gas stations would mess up Yamaha's and other outboard. Or is this just a scare tactic ?!?

Thanks "will fish 4 food" and "Tin Can" -glad you found the ethanol information useful...
Regarding "Aquaman's" Yamaha question, I too have heard of more problems with Yamaha engines, but I think it's just a coincidence.
All the major outboard marine manufacturers
now approve of use of E10 alcohol fuels in
most outboard engines.
(excludes certian fiberglass tanks prior to 1992, and several older outboards when parts were used that were not designed to resist alcohol's solvent affects.)
The real issue/problem lies with the mixing of the ethanol into the gasoline at the correct percentage. (Mixing is done at the pumps by the delivery truck, not at the oil refinery). Numerous stations are (illegally) selling fuel that exceeds the legal maximum of 10%.
(Said another way, the delivery truck driver "screwed-up" and mixed in a too high, dangerous amount of alcohol/ethanol).
Some reports have revealed as high as 40 % alcohol at public gas stations, which could destroy any outboard engine, new or old.
This is why I'm busy advising/educating all boat owners to "test their fuel for alcohol content percent" before buying it at the pump.
10% and lower is safe.
I've also been busy "politically", trying to get laws passed that would require stricter monitoring of the fuel at the pumps. Right now nobody is checking up on the percent alcohol mixed in, present in the tanks - it's just "voluntary" monitoring.
If we could solve this issue, almost everyone would have absolutely no problems with E10.
To make matters worse, if you unknowingly use gasoline with over 10% alcohol (ethanol), and it damages your engine,
it WILL invalidate your warranty...
Yamaha, like all other outboard companies have an ethanol statement that says something like, "Gas containing ethanol can be used if ethanol content does not exceed 10 % and the fuel meets minimum octane ratings..."
Some outboard models
have not yet succeeded in replacing/re-designing all the parts that are
not resistant to alcohol, mostly certain plastic and rubber parts---(everyone's already heard about the engines prior to 1992, that have fiberglass resin tanks that dissolved).
Same goes for type of fuel filters installed...water separating fuel filters with 10mm or greater are an excellent precautionary measure with alcohol (water-absorbing) fuels.
Newer engines use this type of filter, and sometimes even have water sensors installed too.
I have no literature that states Yamaha has a greater risk, than any other brand outboard, with ethanol. Some people (unofficial) have mentioned that Yamaha's "very clean" fuel system design, results in filters, carbs, etc. clogging quicker - but ethanol is an advantage in this situation, since ethanol too has a "cleaning solvent" affect...which will keep your engine cleaner, in the long run.
When switching over to alcohol fuels, you'll notice filters may need to be changed more often (if the engine has any old dirt or build-up), but once old sediment/rust/corrosion, etc. is gone, ethanol fuels run much cleaner.
Stay away from fuels with more than 10% alcohol, that
will disintegrate parts eventually, and you'll be just fine.
Check my site or private message me for more specific details and precautions, damage reports, fuel recommendations, affect of high alcohol, etc. - (Too many details, to be able to completely explain on a board).
Wish I had more time for boards, cause every "boating" site I've been to recently, has lots of incorrect info/scare tactics...I'm trying to address this one-by-one, so people know the truth, which is not "scary", just worrisome and maybe a little inconvenient.
Same goes for the
incorrect info found everywhere that Star*Tron and E-Zorb can miraculously "fix" bad contaminated fuel - It's not true! - More on that another time...
The 2 most important precautions you can take are to Test Fuel, (only use 10% or lower alcohol) and to use CLEAN FRESH GAS.
Gail