Small boats again...
I used my Avon 3.10 over the summer with and without fins.. I only used a 10HP mariner and yes the fins allowed it to get ont he plane quicker with especially with 3 people onboard.. I even towed a Knee boarder and just about managed to do it..
I did try it with a 6 HP Johnson.. but the engine would not rev to full power unless the hood was off and the fingers were in near the flywheel!! But again with fins on it did get on the plane quicker than a 4 stroke 9.9hp Mercury I used on the same boat!!
$ strokes should be banned they give will give a hernia trying to carry them!!
Advanced Power Boat Instructor