No, nooooo and I don't remember seeing that so far.
No you can certainly NOT replace a GY6 style with an industrial engine 'just like that'
you will need to mod the entire back of the kart
(also the 90cc two stroke has more power than the predator.. just saying)
And yes that does include the sprocket of course, since the engine it has is not only internally geared (which the predator is not) it also has a CVT which the predator lacks of course
and not even a Torque converter (the industrial engine's equivalent to a CVT [continuously variable transmission])
isn't helping being up to par with the internal gear reduction.
So no matter what you must replace the axle sprocket (to a much much bigger one!)
and the akrt will end up being slower in the end.
Anyways.. you can however install a 4stroke 125cc gy6 if you're so inclined.(even a 150cc should still fit)
that is the slightly larger slightly more powerfull and slightly quiter engine.
IF you can keep the axle sprocket with that depends on the chain .. otherwise it'd be okay.
'sid