The zen 7 from the UK makes a true SAE corrected 7hp...
that engine was dynoed by an independent and it was no where near 7 hp
The world record is held by Quick Draw, the nearest zen record is 10 mph slower. You won't convince anyone that the zen makes more power than the QD.There is only so much you can get from a zen and the top engine guys in the US are getting all that can be wrung out of a zen.