I have a Bayliner 185 with a Mercruiser 3.0L Alpha1 Inboard/Outboard and when I turn the ignition switch It sometimes start and other times the starter will just click. If I keep turning the key on and off sooner or later it will kick over. I cleaned the battery terminals and made sure the wires on the starter are tight. Is this caused by the ignition switch or is it the Starter?