Here are two reports I enjoyed reading while gaining a generous amount of knowledge on the subject. If you don't like to read, you should skip to the "Conclusion" section for a quick summary.
1. This one was conducted using a Briggs powered lawnmower.
http://web.utk.edu/~scurran/e85kart/Retrofit of a Briggs and Stratton Small Engine to Run E85.pdf
2. This one was conducted using a Honda GX340 Horizontal engine.
http://www.michigan.gov/documents/CIS_EO_Control_of_Emissions-E85-Final_AF-E-_87915_7.pdf
1. This one was conducted using a Briggs powered lawnmower.
http://web.utk.edu/~scurran/e85kart/Retrofit of a Briggs and Stratton Small Engine to Run E85.pdf
2. This one was conducted using a Honda GX340 Horizontal engine.
http://www.michigan.gov/documents/CIS_EO_Control_of_Emissions-E85-Final_AF-E-_87915_7.pdf
