going fast is fun, but for me that’s not the real reason to want a bigger motor on a tiller boat.
i’ve owned a 17′ tiller w/60hp, a 17’6″ tiller w/70hp, and a 19′ tiller w/90hp. i’ve ridden/fished in a bunch of 20′ rigs w/115hp motors. i now own a 20′ Skeeter with the 150hp Yamaha.
each one of the “underpowered” boats was fast enough for me when running in the 30s. and each of them also struggled when it came to hole shot and mid-range juice, especially with a standard load of people and gear. and if the weather was humid? forget it.
when the seas are rough, i want my motor to have enough spare power so that i can respond quickly when needed. sub-20′ boats using the coast guard formula, as well as 20′ rigs with the 115hp motors just don’t have enough for me to be comfortable. cruising speed for the hull is going to be the same, but the smaller motor is working much harder all the time too.
i’m currently in the 20′ Skeeter with the 150hp Yamaha. it’s plenty fast at 47-48mph, but more importantly it’s got enough spare power to safely handle a heavy boat on big waters like Green Bay, Leech Lake, and Lake of the Woods when things are rough.
i broke my power steering once already and was able to replace it. i’m worried about what will happen if/when it happens again and there’s no replacement to be found. re-rig with a 115hp? re-rig with a Mercury? let’s get that new steering system Yamaha!