Darwin,
Wow, this engine brings back some fond memories for me, similar to the food critic in the movie 'Ratatouille' when he is served a dish of the same name...
I build my 1st motorized 8' wood skateboard with this engine w/ v-belt drive when I was 15-ish. Then it morphed into a foot steer go-cart, then found its way onto my very 1st motorized bike named 'The Pooch Mobile' (also w/ v-belt drive). It later ended up onto 2 different chain drive mini-bikes before being sold to a neighbor kid while still running strong after many, many miles.
A bit heavy but awesome!
Thanks for the flashback,
-Low-