Re: Four Strokes???
Muddy - a couple of things to consider: the WET weight numbers(includes lube & gear oil, fuel, water, etc.) are what the boat will feel; this adds about 30 lbs. Most of those 4 strokes hold 6-7 qts of oil (7.6 on 150 Suzy), so they're really closer to 500 lbs ready to run; even more for the Verado. Would be interesting to launch the bare hull and then put some ballast in back, like a big trash can full of water, to determine effects of increasing motor weight on trim!
Need to consider effects of balance on how the boat rides, esp. in rough water. You're certainly going in the right direction by moving fuel tank forward. On my Seafari, the big flotation tank in the Seamark bracket largely offset the weight increase from my old 300 lb V-4 to the 427 lb E-Tec and the 30" rearward shift in mount point, maintaining acceptable STATIC balance and self bailing capability(new waterline is within about 1" of old one). However, when you're up on plane and the flotation tank is out of the water, the boat KNOWS there is more weight back there! Can't fool mother nature - the basic laws of physics still apply! At a given setting on the power trim, it does not seem to ride quite as well as before, although I am able bring the bow down with power trim a little better than before. (Must be something about the geometry of 25" shaft and/or bracket that provides more leverage.) Bottom line is I'm VERY glad I did not go with a heavier motor. Recent forum posts about the "bow heavy" O/B Scepters riding better than the cc's seem consistent with my experience. Remember the 20' hulls were designed in the mid 60's before the V-6's came along, so the biggest OB's were about 300 lbs. The relatively narrow beam that helps them ride so well compared to the newer wider boats also makes them more weight sensitive. I'm convinced that the ride progressively deteriorates as motor weight is increased from the original 300 lb. number. You might want to reconsider the new DI 2 strokes . . fuel consumption is now very competitive with 4S, they idle great, no longer smoke or foul plugs, are easier to maintain, and the initial problems they all had seem to have now been solved.
Good luck with your project; I know the motor selection decision is a tough one as they are all pretty good!
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