OK, so - I went to autozone and bought the token $49.99 starter, starts perfectly, and i diddnt even need that expensive top mount gear reduction  ..

My question for you guys - during extended cranking, the ground gets HOT.. like melting the plastic hot. its 4GA.. Ideas? It's currently grounded to the block/harman marine bellhousing peice via a bolt. Should i move the ground to the actual block, or just run a thicker ground?

also - boat is going to have two batteries, should i run a ground off each side of the block to the batteries, then just use the selector switch, or what?

Where ever the cable gets hot is where your loose connection is, I always use 00 (double ott) wire and yes, both batteries get their own ground and the hots go thru the switch..

GT

perfect. kicker is, the cables arent loose. Do you use 00 for the positive as well?

Ditto to what Glenn said and I'll add I alway run ground leads to the starter and the alternator along with leads to the block.