You are welcome to the props. What prop did you try? You can help with the heat problem at least a little .If you solder tubes to the motor terminal tabs and hook up your cooling line to them . There is several problems in getting these boats to run better. The hard plastic hull is heavy. Much of the weight is too far forward and the boat runs too wet. If you had a gear reduction ,you could use the bigger props without burning the motor. There are brushless options that would work and be cheap too.
n.h.schmidt