73 SS HP vs getting on plane

[txbandit44]

My 16 ft ss has a 70 evinrude on it now. Looks like im gonna need a new/old motor b4 she gets on the water. This is going to be a fishing cruising rig. No pulling tubes or skiers. Im thinking 4 stroke but my get stuck on another 2 stroke.

I figured 4 stroke mostly for the quiet ride. I like to hear myself think when im trolling.

BUt to the question. How much HP do i need to get up on plane. I'd say never more than 1000lbs in the boat and that would be rare to have 4 grown men and gear in the boat.

 

[elkhunter338]

Re: 73 SS HP vs getting on plane

My guess would be 50hp 2stroke, 65 hp 4 stroke, but a prop makes a big difference and your altitude. You loose I believe 3% per 1,000 feet.
I am guessing most boats plane good at 20mph, so you need a motor that will run wot rpms at 20 mph, this would be your minimum.
I think older motors where rated at the power head, newer ones rated at the prop.

 

[Pugetsound]

Re: 73 SS HP vs getting on plane

My 16 SS 1975 had a 50 hp Johnson and with two in the boat would plane at 34 mph 141/4 inch prop 19 pitch. It was rated for a 90 but sure does not need it. Check your prop and, it may be slipping in the hub. No reason at WOT mabey 4200 rpm not to plane nicely.

 

[veilside180sx]

Re: 73 SS HP vs getting on plane

My Yamaha F50 4 stroke does 32 mph with 2 of us in it.

I'm sure you could easily plane out with a 40 hp 4 stroke and 2 guys.

Crabbing last weekend definitely was interesting with 5 adults and 9 crab pots (and a cooler full of crab). I had to shuffle people around so I wasn't plowing, rather than planing. It was the first time I've ever had to do that.

 

[Chinewalker]

Re: 73 SS HP vs getting on plane

First year I had my 16SS I ran a 1957 Evinrude 35 Lark on it. Ran beautifully with one or two people! Any more than that and it was pretty doggy. It was the only long shaft motor I had at the time - I replaced it with a 1980 Johnson Stinger 75 that following winter.

 

[MichaelP]

Re: 73 SS HP vs getting on plane

I'm running a 40 Suzuki 4 stroke on my 16' SS. With 2 adults and gear it jumps on plane fast and tops out at 34mph on the FF. I'm very pleased with this set up.

 

[txbandit44]

Re: 73 SS HP vs getting on plane

Thanks guys.....Hey Michael how do you like that suzuki? I got a dealer down the road with them but havent seen many people around here with them.

 

[Pugetsound]

Re: 73 SS HP vs getting on plane

??? is your present motor a 70 hp or a lesser hp built in 1970? As I said earlier you shoud need no more of a motor than yours if its tuned and the prop is right.

 

[txbandit44]

Re: 73 SS HP vs getting on plane

It has a 1974 evinrude 70 hp on it now. I have only had this boat for 2 weeks never had it in the water so i have no idea how it performs with a 70hp. This is my first starcraft and first big alum boat. Im in the process of replacing the floor, swaping out the crap highlander trailer for a better one and trying to figure out if the motor is worth saving or not. I just got a starter for it and it has the following compression readings #1---105psi #2 150psi #3 135psi. Im concerned about the motor since its got such a low number in #1. I didnt have TW3 oil onhand so a few shots of wd40 is what i used durring the compression test. Im going to retest with tw3 oil before i call it quits on this motor. I have had a lot of experiance with the 3 and 4 cyl johnson and evinrude motors. All of witch have had the same thing in common LOUD!!! Dont bother me at all but the kids and wife hate it.

 

[Pugetsound]

Re: 73 SS HP vs getting on plane

You need to get the Motor running if it will for a while then do anoither compression test. If its been sitting it may have just a stuck rings on # 1 cyl. good luck

 

[txbandit44]

Re: 73 SS HP vs getting on plane

Thats the plan. for now. Im just trying to get my ducks in row and find out what is going to be the best fit. That way when i see a screaming deal on a motor I will not have to waste time reasearching and have someone beat me to a good deal. I hate that.

 

[ezmobee]

Re: 73 SS HP vs getting on plane

If you can get the compression to even out on that 70, you've got pretty close to the ideal motor for a 16' SS.