Minimum HP recommendation

I am in the market for a new (to me) outboard for my 1979 Starcraft Mariner. Boat is rated for up to a 150 hp. Would a 90 hp outboard be enough to push the boat around effectively? Or will that not be enough? Any advice is appreciated

What is the weight of your boat? Length and width?

1250 lbs
21' long
7'11" wide

The 1979 mariner 21' was rated at 150 (125 for the 18'), with a dry hull weight of 900 pounds. I'm a firm believer in maxing out horsepower whenever possible, but I understand that it isn't always possible.

At a minimum I would think 70/75 would be needed for that hull and it likely would only work with light loads. 90 would be ok, 115 even better.

I've run 60 and 70's on flat bottom 2060 work boats that have weights in that range and been favorably impressed with the performance. Yours being a V will require more HP. I would think the 90 should be a minimum. and would seriously look at a 115 if funds allow.

A 9.9 would push that boat around. But if you really want to move a bigger motor would be better. You have more options to go faster with a bigger motor. It all depends on just how fast you want to go.

I had a 150hp on the boat and to make a long story short, I sold the motor for parts. The 150 was nice and would move the boat at 45-48mph. Ideally I am looking for a 115-150, but came across a good deal on a 90. I will be using the boat for fishing and duck hunting Lake Erie, so a kicker and heavier loads are definitely in the future

Standard thinking is 75% on the max hp rating is the minimum, so 115 hp.

I too would probably go with as big a V4 OB I could afford ...

I had an 18' Lund Tyee of similar dearise and hull, double-thick running bottom plates, with a 90hp on it and she would turn 45mph, w/ OB off a CMC tilt/trim unit.

Thanks for the info guys. Appreciate it