I know this bike...It was the subject of a magazine article a few years back which contained some ...err...novel theories on engine tuning. He also made ludicrous (and unmeasured by a Dyno) claims for the power produced...about the same figure at the crank as a 'works' DBD34 Gold Star. Note that the inlet port has not been moved..a key requirement to getting power from a sidevalve...
I quite like the look of the bike...very 'classic sprinter'...but I'd love to see it on a dyno. I suspect it won't be quite as much of a beast as the description infers..
I do like this bike. But as Ian side I really cannot see how its radically tuned at all. Have a look at some sidevalves that really put up the numbers. They haven't addressed the shortcomings of the sidevalve.