Flying a 2-stroke Ultralight on E-85?

Can a 2-stroke Rotax be flown on E-85. I intend on doing so. I will attempt to log my progress on what I have done and how it goes here.

Oil/lubricant

There are oils that are definitely not compatible with E-85. I am an Amsoil dealer and user. I contacted Amsoil initially and they stated that none of their current 2-cycle oils are compatible.

My dad actually mixed about a pint to see what it would do. It appears that after a day or so that the conventional 2 stroke oils can actually break down or seperate into different components.

I am using for VP Racings RC3. This is a refined castor oil. VP's claim is that it is degummed. Castor oil will seperate back out of the alcohol under a number of conditions. Low temperatures( under 35 degrees or something like that) or if the specific gravity of the fuel is below a certain point.  What I have decided to do until I have more experience with the fuel is to drain the tank after each flight. This will allow me to re-mix the fuel(i.e. shake it) before my next flight. If I knew for sure when my next flight would be and it were to be less than 48 hours I probably will leave the fuel in the system. For now though I will drain the tank between flights.

Carburetion

I have rejetted my Rotax 447 Single Carb to the following values.

Jet	Gasoline Jet	E85 Jet
Mid-range Jet	2.74	2.80
Idle Jet	45(I think is what it was)	65 or 70
Main Jet	165	210

Arriving at the above values was done over a period of about 2 hours of ground running. Running the engine through all power settings and monitoring Cylinder and Exhaust temperatures.

Initially I started out using the 2.74 midrange jet and a 230 main. These settings allowed me to maintain reasonable temps but I was unable to richen it in the 4000-5500 rpm range below 1100. I was at full rich.  When I switched the mid-range jet to the 2.80, the full power mixture was too rich. The EGT was running about 950 at full power but the engine was producing a stutter and was turning about 200 rpm below what I had been producing. I switched to the 210 and the full power stutter went away and was back to the same RPM  that I had with the 2.74/230 jetting.

With the 2.80/210 jetting I am now able to adjust the mixture in the midrange to richen the mixture between 950 to 1150 within the limits of the in flight adjustable needle.

Costs

E-85 costs in this area is priced about the same to 15 cents less than 87 octane auto fuel. E-85 has an octane rating of 105.  The RC3 castor oil is expensive relative to conventional gasoline compatible oils. RC3 costs around 8 US dollars a pint.

Flight Time

Date	Time	Notes
May 28, 2006	approx 40 minutes	Mixed 4 gallons of fuel for planned flight. Max altitude 2500 AGL. I varied throttle with several full power climbs and majority of time at RPM between 4500-5000. EGT/CHT temps were well within acceptable limits. CHT at 5400 RPM never exceed 400 degrees with majority of the time temps running 375. After flight, drained remaining fuel and had about 2 1/2 gallons left.  Temperature on ground at time of flight was about 95 degrees, humidity 55%.
May 30, 2006	approx 45 minutes	varied altitude and power settings.
June 3, 2006	approx 30 minutes	half hour flight home to keedot and back. max altitude 1200 agl.
misc dates during summer	approx 2 hours	lost track of where, when and how. still flying I'll attempt to update the approx time on the run time of this row as I go along during the summer. No problems or difficulties at this time. 7/26/2006
Hernia Surgery	Flying stopped 9/11/06	It is now 10/28/06, doc has released me but its nasty cold and rainy. I told myself when the temps got below about 50 I was going to convert it back to gasoline for the winter. So no updates will probably occurr until spring. Total time of E85 flying somewhere around 10 hours with no issues.