My boat won't plane off

The first thing I do is check to see if it's an issue with the prop.  This is almost always the case, and if so, its an easy fix.

When customers call with this problem, I ask them, "is the engine RPMS reving up but the boat not going any faster?"  If the answer is yes, it is most likely a spun prop hub wich means that the rubber that connects the inner or splined part of the prop to the outer, blade part of the prop is slipping.  If that is the case the prop can be re-hubed or replaced.

The way I check for a spun prop hub is to first look at the rubber area, if it lookes chewed up or melted that would be a good indication that is the problem.  If it looks OK, I will make alignment markes on the inner and outer parts of the prop, test run the motor to duplicate the problem, then recheck the marks to see if they are misaligned.  If they are misaligned, then the hub is slipping.

If the answer is no, the motor is not going to full power.  This could indicate anything from the bottom of the boat being fouled to a blown cylinder.