Check this article out and pay attention if this might be a problem for your boat: http://www.boatus.com/news/e10_0706.htm

I have a plastic gas tank and my outboard motors manual recommends  10% for normal use.

Lucky me.

We have E85 (85% Ethenol / 15% Gas) here in Nebraska. I wonder what that would do to my outboard? :-? Scary thought because in that article it said that 25 hrs of light use with E20 would cause problems. I would not like to see the bill from the repair shop with my brand new motor!

Wow 85% ethanol. That can't be good.

We had the change-over here in the Tidewater area of Va. a couple of months ago. I didn't waste any time getting hold of the folks at Yamaha about what to do if anything. They quickly told me to install a 10 micron filter (water/fuel separator). Also to use a stabilizer and the other recommended lubricants. There is a notice about this Ethanol on their website. Yamaha DOES NOT recommend using the E85 blend.

I know first hand of some folks who have had trouble using the Ethanol blend. My buddy had the filter installed on his rig and it was only a short time until he had problems with clogging in it and the in-line filter on the outboard. Other folks are experiencing problems with poor engine performance.

I don't know what other motor manufacturers are recommending. I did a search for Evinrude and Johnson and came up empty.

So far I have had no problems since having the filter installed. I have not topped off my tanks as yet so am not too certain that I have a mix of old and new blends.

Doing some research we found an additive that absorbs moisture that is available in the NY area. So far it is not available locally. You can bet that once it shows up here I will be adding it to my tanks.

This appears to be a big problem in the making. Definitely a case of "an ounce of prevention beats a pound of cure".

Take heed folks. This stuff is nasty in outboards.

Shortbasser

so...can you use some kind of gas treatment like STP on a 2stroke outboard to get rid of the clogging and black gunks?

I wouldn't be using any STP. The only additive that I have found specifically made for this Ethanol crap is a product called K100 made by Kinetic labs. check out their web site at: www.k100fueltreatment.com/ethanol.html. I run a Yamaha and they recommend some normal additives to the gas. Also have that 10 micron fuel/water separator installed. That is needed since the Ethanol creates moisture.

I have no idea what the other motor manufacturers are recommending. You need the filter to block the crud that is loosened from the tanks once you have to start using the ethanol blend. That would be in addition to the in-line filter that is no doubt on your outboard. Check the above article and that Kinetic Labs web site. You should get a big picture of the problem and recommended solutions.

Shortbasser

I was told the same thing by Mercury...use a good 10 micron filter and they suggested a couple additives I cannot remember the name of... ( I could not find them near me) and fuel stabalizers...

BUT...they said to be careful the make sure that the stablizer and or additive does not contain any alchohol...I guess alot do...

so far the only ones I found that do not are Miracle oil and Lucas....but have not heard back from Mercury whether they are okay to use or not.

I just finished a summer speech class and used ethanol and biodiesel as my topics. I did some research and found an article by Mercury that talked about ethanol in their engines. Basically, all of the engines are manufactured to run up to 10% ethanol. Beyond that they said stay away because the engines were never designed to run E85. They same is also supposed to be true for small engines like lawn mowers. Right now there is also alot of bad information about ethanol and its many blends. Here's the link to the Mercury article which was written by their engineering staff. http://www.mercurymarine.com/ethanol2

If you have any other questions let me know I learned more than I may ever need to know about alternative fuels.

bassdocktor

I'm sorry but if people put E85 in their outboards gas tank they are dumb enough to put diesel in it, too. ;D