Re: How fast will a 17 ft runabout with a 65 hp evinrude go
Its a complete guess but I would say its going to be similar top end speed. You may get an extra 5mph over your 14ft, but I doubt it would be a ton faster. So much depends on load and displacement of water, without knowing your hull weight, load weight, prop pitch, and max RPM on the motor--its just a complete guess.
It really depends on the weight/shape of the craft. There is a formula you can use to determine your approximate speed using the weight of the boat, prop pitch, and max RPM. I'm not 100% on what the formula is, but there are several postings lately that have the formula is it. That is going to be your best bet to figure your speed out.