I found out that the enduro karts in the World Karting Association's events reach jaw-droppping speeds of 140 mph!! Check out the racing action starting at 2:20 in this video. These are insane speeds considering the lack of any safety features in the karts. They don't even have a rollbar, wow!
These karts weigh only 465 lbs with the driver and use 100cc 2-cycle engines, which can be wound up to 16,500 RPMs. I am just amazed to see these little karts go so insanely fast at Daytona. And I thought 50 mph in the kart enduro that I did was already pushing my sanity limits. I'd be scared to try these as I suspect I'd be totally addicted to them. Kudos to the guys who have the guts to race them!