Water Skiing Power

dwcooze

Recruit
Joined
Jun 12, 2012
Messages
3
I am looking at purchasing a 1991 17ft Invader V171 bowrider, 2.5L Merc I/O [120 hp]
Can I tow a skier with this boat? If so can I tow a skier with a 4 people in the boat?
What about pulling up a slalom skier?

I had a 15ft glastron with a 60hp outboard, that could pull a skier but not easily.

Any suggestions would really help.
 

oldjeep

Admiral
Joined
May 17, 2010
Messages
6,455
Re: Water Skiing Power

You can pull a skier on 2 skis with a rowboat and a couple strong guys ;) Getting a slalom skier up with 1 in the boat should be fine, with 4 in the boat is going to depend on the skill of the skier and how much of the original 120hp that boat still has. Slalom skier is going to pull a 17ft around a bit.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
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49,804
Re: Water Skiing Power

if you do a lot of skiing, the 120 will not cut it. pulling the occasional skier, you may have to move people to the bow to get the boat on plane.
 

haulnazz15

Captain
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Mar 9, 2009
Messages
3,720
Re: Water Skiing Power

Bah, 120HP will get you and 3 friends around the lake just fine. I am over 200lbs and have gotten up on slalom many times behind a 17' bass boat with a 115 Merc O/B, with 3 180lbs guys in the boat. Granted the invader will weigh a little bit more, but you should be alright. More power is always better though.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Re: Water Skiing Power

you can not compare skiing behind a 115OB and a 120 I/O. skiing behind an OB is easy. they weigh 400# less, have a better hole shot, and a better top end (because they spin 1500 rpm higher).

I have skied behind my own 140 I/O and it struggled pulling a slalom skier with more than one other person in the boat. can you do it, yes. is it enjoyable - not so much
 

haulnazz15

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Mar 9, 2009
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Re: Water Skiing Power

Sure you can. HP is HP. The Invader likely gets on plane much better than the Quantum bass boat I was skiing behind. The I/O will make its torque at much lower RPM's than the O/B which is what will get you out of the hole. Better top end is irrelevant (within reason) to slalom skiing as we aren't running WOT unless you like skiing at 40+mph, I don't venture much past 32-34mph. I didn't say that it was easy to get up behind a boat with those engines/weights, but it's doable. I would also mention that we had a 3-blade speed prop on the O/B which made hole shot even more dismal, with the weight being about 250# different between a Merc 120 I/O (650 lbs incl outdrive) and a Merc 115 O/B (~400lbs) from the specs I've seen. I'm not arguing one over the other, I'm just saying hauling 3 friends and a slalom skier is possible.
 

skibrain

Senior Chief Petty Officer
Joined
Jun 17, 2004
Messages
766
Re: Water Skiing Power

There are so many other options that would be better for skiing. 4.3 V6....135-150hp outboard
I'd say the 15' Glastron w/60 hp outboard is a waaay better bet than the i/o you're looking at.

If HnA's numbers are good, that's 250 lbs right were you don't want it. At the back of the boat. HP might be HP but I would sooner compare an old 120 i/o with a 75 hp outboard. Maybe. Either way leave all but one friend on the doc.
 

haulnazz15

Captain
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Mar 9, 2009
Messages
3,720
Re: Water Skiing Power

I agree, there are much better options out there for sure. But can you get by with that rig? Of course. I don't prefer less than 200HP no matter what the drive type is. :)
 

jkust

Rear Admiral
Joined
Aug 2, 2008
Messages
4,942
Re: Water Skiing Power

Think about it...what do you think they did in 1991? They pulled skiers. Sure there's going to be something better but i'm presuming that if you are looking at that boat you are budget limited. We grew up pulling doubles and triples with an 85hp O/B with three in the boat with aluminum, three blade props. When the driver is good and the skiers are as well you don't even stop the boat to pick up a fallen skier. You can make due with that boat. Also that engine's HP is rated at the Flywheel not the prop like modern engines are so would be less than 120 comparing apples to apples.
 

skibrain

Senior Chief Petty Officer
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Jun 17, 2004
Messages
766
Re: Water Skiing Power

I don't need to be convinced that you can do alot with low power and have a GREAT time making about anything work.
I've been skiing since 1968. I grew up skiing being 20 hp. Then 40 hp. A buddy w/50 hp, another with 85 hp. I was 19 before my dad traded up from the 40hp. Tube, combos, slalom, leave some people on the dock if necessary. I made an attempt to ski behind my BILs fishing boat with 30 hp last fall - would have worked but he had the wrong prop. I am definitely not a snob in terms of boats. But whatever the budget is, since you don't own this boat YET.... for that same modest budget, there are probably better options for getting a slalom skier out of the water with 4 passengers in the boat.
 

*mtrbtr*

Cadet
Joined
May 1, 2011
Messages
19
Re: Water Skiing Power

If you do end up getting this boat, just budget in a new prop. I had a 2.3 liter four winns and had a speed prop and a prop pitched differently for more torque. High end speed was probably 36 miles per hour but it pulled anyone out with a full boat just fine. Different pitched props is just like having 2 different gears. After a while we never even used the speed prop, no need because we were always skiing.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: Water Skiing Power

Can you do it ....yes.
Will you be looking for a more powerful boat soon after or wishing you had got something with some more "woomph".....Yes.
Just my thoughts though.
 

amr40509

Recruit
Joined
Jul 18, 2006
Messages
1
Re: Water Skiing Power

I think that as long as you don't expect too much, you'll be OK.

We ski with a 22' alum. deck boat with 115 E-Rude outboard all the time. I've deep water slalom started and skied MANY times behind it on 1 cheap combo ski with 7 people in the boat (boat rated for 8, and I'm the 8th). So it's a LONG drag to get up and max speed, boat wide open, is about 32-34mph with that load, but it works.

Sunday we had full gas, a couple of big coolers, 4 adults + 3 kids on the boat. One other guy and I skied - when I took a run (2 skis since the bmini top was open to provide shade for the kids and we don't like to run over about 25 like that) I popped right up and never even got my sunglasses wet during the run.
 

jkust

Rear Admiral
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Aug 2, 2008
Messages
4,942
Re: Water Skiing Power

When we were kids, we had boats like we had our own bicycles to get around the lake. Many, many times we kneeboarded (back when it was in) behind a 9.9 Merc. Point being it doesn't take much to have fun.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: Water Skiing Power

When we were kids, we had boats like we had our own bicycles to get around the lake. Many, many times we kneeboarded (back when it was in) behind a 9.9 Merc. Point being it doesn't take much to have fun.

Agree, it does not take a huge amount of power to have fun. My point was that with something that you may get bored with in a short space of time it may be better to go up a step ot 2 to begin with.
Just my thoughts though and each to his or her own.
 

capecodtodd

Petty Officer 2nd Class
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Aug 11, 2010
Messages
128
Re: Water Skiing Power

When I was a kid and weighed probably 100 pounds wet I used to ski behind my fathers 14' aluminum v hull with a 25 HP evinrude.
In my skiing/ watersports heyday I had a 18' bowrider with a 6 cylinder 175hp I/O and we used to pull 2 kneeboarders with ease with 3 others in the boat. I now own a 20 Stingray with a 3.0 135hp Mercruiser and we don't do much skiing anymore but when we do it doesn't pull near as nice as my last boat. I think it is a HP and weight issue, the boats not mine. LOL
Something that I added to both boats and I think worked very well was one of those Stingray whale tails. You will get up on plain faster and not have to mess with your trim, up faster means less fuel used and less strain on your skier as he tries to hold on.
I too think the more power the better why put so much strain on a little engine. A slightly longer boat will also be alot more comfortable too.
 
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