Have a perko switch - when in "both" position, boat won't start. When in "1", boat starts. When in "2", boat starts. I'm no expert! Seems strange to me, but undoubtedly someone here will have the perfect explanation.
Both batteries are original with the boat - 3 years old.
Time for new batteries? Does bringing two slightly undercharged batteries online somehow weaken the overall power?
Thanks for the help!