On Sat, 06 Sep 2008 15:34:05 -0400, jim wrote:

tomtemp937 wrote:
I have a a pair of 2006 Honda 225 with dual batteries and batery
selectors. I notice when each motor was running on it’s own battery
that the port motor was not charging. However when both batery
selectors were on 1+2 the port motor was charging. After return from a
offshore trip I piullerd the plugs on the port motor and one of the
plugs electrode was smashed . When I pulled the head the center piston
was missing a chunk on the top edge and the piston was badly pitted. I
also noticed the other pistons were were starting to pit. My thinking
is that when the port motor was selected on it’s own battery and the
output of the alternator was not getting back to the battery. It
created a condition were electrolysis started and the pistons were
sarificed? Yes there are other zincs on the motor both on the lower
unit and exhaust manifold. Maybe somebody can shead a little light on
this.

Thanks

Tom

You probably have a bad alternator which could have easily damaged the
ECM in the engine. Not electrolysis's but preignition. This is wild
speculation on my part as I have zero knowledge of those engines.

A strong possibility though.