I am considering repowering my 17' whaler with a 90 hp etec. I have been running for years with a 1979 115 evinrude. To my surprise the Etec 90 is listed at 320# with 20" shaft. But my service manual for my old motor list the weight at 301#. Why is the three cylinder etec 19#s heavier than my old motor? I really would like to reduce the weight but I would have to go down to a 60hp etec to find a motor lighter than my 115hp.