starting problem

[deshet]

My boat is doing some weird things. Sometimes the starter continues to turn after I turn the ignition key to off. (only after it failed to start) The starter often acts like it does not have enough juice to turn over properly.

I have replaced all of the power and ground wires from the transome back including all outboard connections.

I have had the starter rebuilt....I took rebuilt starter to Advance Auto and they said that the starter is good and it is pulling under a 100 amps

I have also installed a new starter seloniod.

The boat has two new batteries and when I attempt to start both batteries are on.

thanks in advance for your help