The time is getting near when I will need to replace my 1985 Mariner 25 hp o/b. I have it on a 1448mv Polarcraft and it has served me well. Because everything now in that hp range is 4 cycle, I have been researching different motors, specs., hp ratings etc. The more I read the more I become confused about which motor to replace it with... I would like to list several questions/statements about the four stroke motors and ask for discussions, actual experiences or anything anyone has to say about going to a 4 cycle o/b.
-has anyone replaced a 2 cycle with a 4 cycle (same hp)on an existing boat?
-does a efi (Suzuki) offer any advantages over a carburated engine?
-is there a noticable difference in fuel consumption between the motors if they are run on identical boats/weights?
-if the boat/equipment weight is reduced to compensate for the heavier motor weight is the performance about the same?
-any other issues that I should be aware of.

I plan to get tilt and trim on a new motor and feel this should help some with performace.
Any comments and actual experiences would be appreciated