I am replacing a 9hp motor with a 16hp Chinese motor for a friend of mines homemade longtail, are the out of water rpms like 4200, just like the briggs, hondas and such?

also on a factory longtail, as far as balance goes. when your sitting in the boat and let go of the handle does the motor fall into the boat or does the prop go into the water? I'm talking not moving, just sitting there.

thanks