I was trying to make a point by an absurd claim
yes, 250cc kart race engines are two stroke and deliver a crazy amount of power
roundabout 100 horses are not uncommon.
but it doesn't matter.. you can go slow with every engine in every kart on any wheels..
you can ruin a tyre in no time if it's heavy and/or you're going for a hard off road trip
with a 5horse engine as easily as with a high speed on race tracks.
The point is, you need to tell us what you want to achieve and then we can maybe tell if a wheel is up for the task or ot.
naming just the combustion volume of an engine is
about as relevant as naming the colour of your jacket.
a question like
"Would that tyre survive some careless off roading with a Manco black widow kart equipped with a 23hp 5speed bike enigne?"
the answer would be
"the wheel sould hold up as well as the 12mm spindles your kart's equipped with"
don't be too careless since 12mm isn't that much ..
so avoid jumps and ramming rocks with your wheels.
a question like "would that tyre survive a speed run on the local beach (top speed about 50mph)"
the answer would be "on wet sand.. they should if balanced; same speed on road might overheat the tyre though.."
etc.etc..
tell us WHAT it needs to survive so we actually CAN make an assumption
Now..
with high impact you should worry more about your spindles than your wheels frankly
with high temp we're out of clue, better get a road licensed wheel with matching speed index.
with high speed your wheels must be balanced or they can quickly cause troubles.
but since you're essentially on wheel barrow wheels up front with a 12mm spindle,
you shouldn't hunt for any extreme anyways
'sid