The 250 will be adeqaute but minimal. It will probably top out around 40 - low 40's and feel somewhat lacking holeshot and wave climbing power. Also, I assume its an OX66 yamaha. Because of the wieght and reduced performance that boat will probably yield terrible fuel burn numbers. Definetly under 2mpg. And to answer your 2nd question, no there should not be a wieght problem because they carry twin 150's regularly. I know its a earlier model but wieght should still not be a problem. But to be honest I feel the DF300 would a be a really great match for the 23 reg. Its a great boat! Good Luck