Well those Harbor Freight wheels do give the most BANG for your buck, if that is what you are looking for.
Those Harbor Freight wheels when mounted on a minibike comes with free of charge:
Bearing failure
Rim failure
Tire failure
The last three all at the same time.
Frame damage
Axle Damage
Injury
A trip to the hospital
And last but not least, the cheapest and fastest way to cash out on your life insurance policy.
If that sounds like a good deal to you, I'll throw in the a second wheel for free. Thats right, pay 2x for the first wheel, get the second one free.
Ok, I hope you got the joke. Seriously, these wheels could kill you if you are going fast enough and one of the rim collapses(the front one) and sends you right into a tree head first or (the rear one) sends you sideways into a tree when it locks up. They aren't meant for go karts, and never will be. DO NOT BUY THEM.
Go to any major Go Kart supplier, they will have minibike tires that are rated for minibikes and won't send you into a tree head first, side first, leg first or any other direction the wheels decide on. Find the specifications on your tire and match that to the rims and tires you decide on.