So over the past few months I've noticed that my port 115 Yamaha starts/cranks a bit slower than the starboard motor. I couldn't get hold of a load tester but the batteries were showing 13.4 volts on a volt meter. Since they get worked especially hard during the summer (lots of shut downs/start ups throughout the day) I replaced the 2 batts with the same multi purpose marine batteries I've been using. After swapping batteries there was no better performance in cranking so I'm thinking of new cables; I'm the 3rd owner on the boat and although the cables look good and are not stiff I realize they could be corroded internally.
That's my next move and I'm also considering an ACR as well (per Spoiled One's recommendation). What I now have is just the 2 batteries wired into a Guest 4 position battery switch (off-1-2-all). For the 3 years I've had the boat I've always run the switch on "all" and it's been fine.
I'm open to any suggestions or improvements on this.
Last year I rewired everything leading to the wheelhouse but left the engine wiring and battery cables alone. Time to do it differently?