"Yep - you could probably get
"Yep - you could probably get away with a 90 horse if you didn't want to top 20 mph.
A 115 should put you up in the mid 20's top end but you may be better suited with a V6 model. Just plain better torque which will get it up and running on plane easier/quicker.
I'm working on rigging a 24 foot walkaround, displacement 2700 pounds and an 96 Merc 135 carb model is pushing it nicely at about 32 mph with 2 persons on board, 40 gallons of fuel (1/2 tank) and 15 gallons of water in addition to the other normal rigging (batteries/safety gear etc)....
You looking at a new or used motor?"