Hey all
Here's the project, as-was.
That's a much younger me (that was back in 2004) on the thing.
Close-up of the back.
Sadly this project RIP due to some kids who thought it was theirs and took it from outside my house one night in 2006.
I'd love to reproduce it, or something like it, to try again with a few other things in mind that I'd had planned for the original but never got to doing.
It'd most likely end up with a Kubota, Tecumseh or Honda engine, or better still a small singlepot diesel. That and higher gearing on a planetary reduction gearbox.
Oh, and to answer your question, it did drop to about 30mpg at wide open throttle (25-30 mph), mostly because it ran out of revs due to valve bounce at close to 7000rpm. Keeping it running with the throttle mostly shut was really quite economical at about 3000-3500 rpm. Stood up it wasn't so good but inverse-square of wind resistance was really killer!
--Phil