IS BIGGER< BETTER???
First a sailboat is just that, it's primary power is wind in your sails, and auxillary power is for negotiating in and out of channels, marinas etc; and a one lunger yanmar is the most reliable little sucker around and one that You can hand crank to start, whereas with the dbl lunger it is impossible!!!, Do you "NEED" a bigger engine? no not really, the only time my little yanmar was deamed useless, is when the current was exceeding my hull speed, or in storms when I wanted to motor in but could not!, so I threw out a couple of anchors, buttened down the boat and sat it out. I've owned my 1982 Hunter 27 for nearly 13 years and twice i had laid up the ship for 2-14 manth periods, without touching anything, just adding new batteries, and the little sucker started instantly always!!! so if You do WANT BIGGER, lots of luck, but it may not be BETTER !!