I was checking out ATKRIDER's 64 Galaxy reference and found some info pertaining to to the karts:
The first known rocket kart was the one piloted by Jack McClure in the late 60's, this kart was powered by a pair of Turbonique rocket engines.
Later other pilots copied Jack and installed also the same rockets that where sold as kits by a Florida company with the same name.
This little karts where stock out of the factory karts most of them Dart Karts with a single or double Turbonique T-16 rocket engines.
This contraptions where so fast that they beat most of the fastest dragsters of his era as is shown in this picture from the Turbonique catalog.
These rockets used a fuel with the name Thermolene but in fact was N-Propyl Nitrate, this fuel is considered a monopropellant of the family of the nitromethane and is very dangerous under certain conditions and these rockets had a little design error and it was that when they where used at full power it was not any problem but if you panic and shut them off and the later you apply full power again then they exploded like bombs killing it's pilot and for this the owner of Turbonique ended up in jail in Orlando Florida.
I have read more than once that people got killed using these things and that legal issues eventually shuttered the doors on Turbonique. That part of it wouldn't be hard to believe just by looking at the components and the lack of any type of scatter shield or secondary containment in the event of an explosion.
Tucked under the back of a full size car you might have a chance at walking away without a scratch...a go kart or motorcycle :doah:.not so much.
It looks like the thing is made out of cast iron, talk about a grenade! I'd say it was a bad idea to market them to the general public. The one on the Ebay ad was sold through an appliance store!