I have a 2012 60hp etec on an 2010 1600 Lund Alaskan tiller. Approximate hull weight is 960lbs. plus 1 person and gear at about 220lbs. with a full 19 gallon tank. I installed a tiny tach and was suprised to find out its maxing out at 6230rpms at full throttle. Im turning the factory 13.75x13...