Gary - I don't mean to rain on your parade . . . but 4.9gph doesn't sound right. I don't think your gauge is calibrated properly. 5 - 5.6 mpg is a little too good to be true for a 23. Strick's 23 with the 250 suzuki was just touching 3mpg flat seas. His numbers seemed to be ballpark for large 4 strokes on a 23. I just don't think that the honda is 80 - 90% more efficent.
Most 23's on Honda's site are posting around 2.8 - 3.0 mpg b/w 3500 - 4000rpm.
http://www.honda-marine.com/pdfs/pro...0-%20BF225.pdf
http://www.honda-marine.com/pdfs/pro...0-%20BF225.pdf