How much mph would a go cart go if it had 150cc?

Answer 1

Simply, not enough information to answer the question. For a very VERY rough, ballpark figure, you would need to know the weight, size of tires, and experience of the driver. For simple exact results go down to the local drag strip (or a long strip of unoccupied road) and run a pass. Or if you don't have access to either of the above options, you could take it to a DYNO (Dynamometer) and have the staff come up with the numbers, as well as the maximum torque, and horsepower. Hope that answers your question.

Best of luck,

Dan