Considering repowering my Starcraft SS160

[ShoestringMariner]

Hey guys I know I post a lot, but I like boat conversations....

Because my old Merc 650 needs much love, which equates to mucho dollars...mucho dollars that could go into a newer setup. I’m having a mechanic give me an assessment this week on whether it’s solid enough.

So if I repower, here’s my wish list, hoping for your thoughts as to what is realistic.

The 65 I have on it goes ok, but I have never had 3 or 4 adults in it yet. Would like more power but also concerned with weight and fuel consumption.

I want to run a small kicker for trolling. I’d also like a motor with tilt and trim. I’m thinking I should be careful with weight with this wish list, not only for hanging weight on the transom, but rear weight (2 motors, battery, 2 fuel tanks).
I do plan to run a pair of batteries up front for a 24v bow mount troller, so a bit of balance, but still more weight overall.

Any my thoughts on what my max transom weight should be?

Any concerns with too much power? I have located a 115 Johnson V4 which I think weighs around the same as an 85 hp Johnson V4, but the boat is only rated for 90hp

How many of you run your SS160’s on less than 65hp? I’ve seen people with 50’s on them.

 

[dozerII]

Try real hard to find a nice 85-90 HP Yamaha 3 cyl , they are a great engine very light for there power and seem to last forever. The V4 Johnny's and Evenrudes are great motors but pretty heavy 316 Lbs if I remember right compared to the 260-270 for the Yammy.

 

[g0nef1sshn]

Just check your state registration and ins laws. Both can be no goes or even tickets for overpowered than manufacturer specs. Ins is probably a def no go.

I put a newer 60 mercury command thrust tiller on mine and half throttle was plenty with my fam and 100lb lab in the boat. I will say for solo rides i will need to relocate fuel and batteries more towards the bow to balance it out.

 

[DLNorth]

115 HP will overpower a SS16.

We have a 1970 SS 16 that I rebuilt the inside on many years ago.
This boat is an oddball in that it has an 18 ft S/N rating plate attached, as best I could learn, from the factory.
The hp rating on the plate is 125 hp. Most SS 16's are in the 85 or 90 hp rating.

I suspect that during it's early life it had a larger motor on it, I say this because the transom was badly bowed out, I assume from the over power.

The transom was still solid when I worked on the boat, this long before even the internet existed much less these boat sites.
I didn't replace the transom but did re-enforce it with a heavy piece of SS angle iron, that runs under the upper clamps and fully across the boat. The angle actually pulled the transom back to straight.

When we got it, it had an old Evenrude 75 V4 on it, clearly not the original motor.
I replaced it with a Merc 850 4 cyl, (later rated at 75 prop), it is a perfect match to this hull. And the then new Merc 850 at 640 ish lbs IIRC was slightly more than the old 75 V4, IIRC that was about 220 lbs.

I also just sold a 1984 Merc 115 that ran great, just because it was too large for the SS 16. (and if I go up to a SS18 it's going to be a I/O.)

Any motor with a 75 hp prop rating will work very well on your boat.

Dan

 

[DLNorth]

Opps, the 850 weight is 260 lbs.

 

[ShoestringMariner]

Opps, the 850 weight is 260 lbs.

So the bowing must have been caused by the extra forces, and not the weight?

So in essence, a V4 Johnson or Evinrude if driven sensibly should be OK.? It’s within reasonable weight range. Full throttle does not need to be used

 

[DLNorth]

I "assume" the bowing was from the extra force from the higher HP, not the few extra lbs of the motor. I "think" an older crossflow V4 OMC is about 300, the 850 260, only 40 lbs, not much difference.

Plus, there are many SS 16's with 85 or 90 V4's doing just fine.

As for not using "full throttle", I couldn't.

There a couple other considerations not yet mentioned.

The SC alum hull is not a performance hull, even with our 850 Merc (75 hp prop) it's easy to be at a speed that is uncomfortable and maybe even unsafe. More power would just make this worse.

The other consideration is that the older motors were powerhead rated, so a 85/90 on a boat is closer to 75 at the prop.
But it doesn't seem like SC changed the ratings when the motor went from powerhead to prop ratings. So if you have a later boat with a 90 rating and put on a late motor with a prop rating, you've gone from 75 prop to 90 prop, or an increase of 15 hp without doing anything.

I thought long and hard about putting my Merc 115 on the SS 16, it was a great motor and near the peak of ToP evolution, but it would have been too much.

 

[Watermann]

It's tough to beat the 3 cyl JohnnyRude motors 70 - 75 HP large gear case on a 16' boat. If you go to the V4 besides worrying over it's weight and power, you'll be adding a fuel tank or 2, they drink the fuel.

 

[DLNorth]

The 70 OMC is a great motor for lighter loads. (note it was prop rated at 60 hp)
But it's a bit underpowered if you are going to ski with larger guys or with a full load of people in the boat.

 

[Watermann]

Yeah no boat is everything no matter what motor it has...that's why I have 2.

 

[ShoestringMariner]

Thanks guys. What’s the smallest motor you think I could get away with? (Fishing duties, max 3 people onboard)

 

[Watermann]

50 bare minimum.

 

[DLNorth]

Agree, 50, if they are light people.
I've fished in a SC 16 with a 50, with 2 it was OK, but you didn't want to have to get anywhere fast though.
Definitely a small water rig.

 

[ShoestringMariner]

Thanks guys. Still keeping my eyes peeled for a deal on 70

 

[Tnstratofam]

The 75hp Chrysler ( Dorm Fridge ) on our SS moves us along nicely at around 34 mph. It doesn't have hydraulic tilt and trim, but it serves us well for fishing and tubing. With 2 adults and 2 kids it works out pretty good.

 

[Rayzor]

My SS160 has a 1982 40 hp merc 2 cyl. and a Honda 9.9 long shaft kicker mounted on the transom. Boat planes out pretty good and will do 25 mph with my son and I. Not for a speed demon but its a good fishing setup on the lakes I fish. Does real well on fuel as well. In a perfect world I would put a 3 cyl 70 johnny on there.

 

[ShoestringMariner]

My SS160 has a 1982 40 hp merc 2 cyl. and a Honda 9.9 long shaft kicker mounted on the transom. Boat planes out pretty good and will do 25 mph with my son and I. Not for a speed demon but its a good fishing setup on the lakes I fish. Does real well on fuel as well. In a perfect world I would put a 3 cyl 70 johnny on there.

You think it will plane out with three adults? Do you use one of those shark fin or whale tails or whatever they call those enhancers to get it up on plane faster

 

[Rayzor]

I have had 3 adults in it plenty of times and it planes out fine. No I do not run a dole fine on it and never really needed it. it breaks over on plane pretty quick. It is a small motor for sure but I wanted it for the simplicity of a single carb etc. The boats soul use is fishing so no dragging tubes or skiers. I may re-power next year with a tohatsu 50 for the benefit of fuel injection.

 

[ShoestringMariner]

Thanks guys, I got my motor out of sick bay. Going to try and make it through the season or two with the Merc 650.
runs great at top end, Seems to have starting and running issues at lower speeds. Going to go through the wiring soon.
was out in it last night, could only get 29.5 miles an hour out of it. With just me in the boat, smooth water, light wind.

can expect much more than that if this motor is running perfectly?

 

[Watermann]

I'm thinking 30 is going to be about it for that motor combo.