Norvel recommends against the Byron fuels. They say the Byron 1/2A blend is OK, but I do not think that is what you are talking about, is it?

Check out the Norvel website. They have lots of good information on fuels and proper engine procedures:

http://www.norvel.com/til/TechNote.T002.html

That will take you to the fuels page.

For what it is worth,
Spiro