make 2002 scrambler 50 to 90
 

what is the difference between the polaris 50 and 90 engine wise? carb, topend, reeds, cdi???? what can i do to make my 50 out run a stock 90

I don't know much about the kids quads but doubt you can make a 50cc outrun something with an engine that's 80% bigger. That would be like my 500 outrunning a 900cc quad. I don't see it happening.

Bore and stroke are different. You can't just swap pistons and cylinders to make a 50 into a 90.If you want something to out run a 90,buy a larger machine.

1.58x1.54 (40x39.2 Scrambler 50
mm)
2.05x1.65 (52x42 Scrambler 90
mm)