T&T: Ethanol recap from OP

[Steve Sipe]

I promised to post the results of my ethanol problems with my Yamaha 15 
four stroke. With guests aboard, and other distractions, the completion 
of the mods was delayed, but another incident with carburetor fouling 
prompted completion.

The carburetor idle jet is the root of the problem, at least in my case. 
YMMV. Any phase separation of the fuel where the water absorbed by the 
ethanol separates and becomes orange snot causes the jet to plug. The 
great thing about all this is that it takes a plug of snot about the 
size of a pin head to work the magic that keeps the engine from idling 
or causes very rough transition from low to medium throttle. It seems 
the *only* remedy in this scenario is to remove the carb, open it up, 
remove the jet & clear it with carb cleaner or by mechanical means. Not 
rocket science, but a REAL PITA, since the engine simply refuses to run 
unless it's run faster than idle speed. Makes for some fine docking.

I continued to use the same gas that I had been using (E-10). I had 
filled with a tank of Valve-tect fuel, which AFAIK, is non-ethanol and 
has the conventional MTBE additive. HOWEVER, the Valve-tect website 
claims only that their fuel has special additives, and does not specify 
that it does not contain ethanol. If you keep in mind that a gallon of 
E10 fuel can contain up to 4 teaspoons of water before it phase 
separates, it's no wonder that E10 is creating havoc in our engines. The 
nature of the portable tank used in the our dinks simply invites the 
problem so many of us are experiencing. I did notice that after the dink 
was hauled aboard for the couple of days we were in Key West, it ran 
horribly rough when it went back in the water. It adds incentive to 
running the engine out of fuel as part of the loading procedure.

I installed the 10 micron filter from Defender as recommended by Stephan 
Lance, also added the PRI-G additive. I have seen no evidence of any 
phase separation in the filter bowl, and the engine has been running 
pretty consistently for a week now. I would add that I still have some 
rough idle and rough transition from idle to higher speed, and plan to 
R&R the carburetor one more time, but am holding off until I get some 
carburetor cleaner to insure that I have all the dissolved gunk flushed 
out, and I intend to get my portable compressor out of the depths to 
blow it all out thoroughly.

Pictures of the filter and the install are on my website link is below:
<http://www.maerin.net/gallery2/main.php?g2_itemId=4081>

I don't know if I'll encounter E10 in the Bahamas, hopefully not. 
However all information I have seen cautions explicitly AGAINST 
co-mingling MBTE and E10. The recommendation is to run out all of one 
before introducing the other.

To recap the solution:

   1. Add a 10 micron inline filter
   2. Run a stabilizer in fuel (PRI-G)
   3. Don't keep fuel for more than 90 days, stabilized or not.
   4. Never co-mingle E10 and MTBE additive fuels.
   5. Thoroughly clean carb after the filter is installed and a few
      gallons of stabilized fuel have been run through.

Hope that helps some of you who may be having similar problems. I know I 
see plenty of folks here in Boot Key Harbor fiddling with their 
outboards at the dinghy dock, myself included! My days of doing that 
hopefully will be eliminated!

Cheers from Paradise where the winds are STILL howling. 37 kts. last 
night's high, 25 steady all night.

Steve Sipe
Solo 4303 "Maerin"
Boot Key Harbor W-8