I know from the kart I made that the $130. 00 motors and controllers bought on e bay just don't have enough power for an adult. The max driver weight is about 70 pounds...they burn out from over heating. The next size motors cost about $4-600 and the controller is another $4-500.
so to get a serious fast and powerful electric ain't inexpensive at all.
Da Flash
Um...I'm (kind of) an adult & I've used that $130.00 eBay (1,800W) motor/controller combo on several karts (with success, I must say)
...the "key" is that they must be "operated within specified parameters"
Ya just gotta gear 'em correctly, to avoid over working & overheating them (or "operated outside of the specified parameters")
* Also, keep in mind that an 1,800W motor is about equivalent to a 1.75HP gas engine?
...& for comparison purposes, has anyone ever had or rode on a 2HP gas powered kart?
Yup, for a "fast" kart your gonna have ta spend a few bucks
...but, having a mini Tesla = priceless
Yup, ~$600.00 for the motor
...~$400.00 for the controller
...& don't forget the battery pack will be ~$500.00 too
**Q:
What does a Stage 5 or whatever upgrade to a Predator engine, end up costing?
...& then, what do you have?
A:
Probably close to $1,000.00 (if not more)
...& then, ya have a 6K RPM, DIY Chinese "grenade", mounted right behind your head
Here is a quick video of my Excalibur kart "doin' donuts"
...not bad for ~2HP