Waterskiing- what size engine for a big bloke

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Homer J

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Apologies. I am a sailing boater and have just bought a 17 ft speed boat (Salcombe Flyer 530).

It currently has a 90hp two stroke mercury but I’m told it’s beyond economic repair (electronics).

I want a good reliable engine powerful enough to pull me up on two skis with 2/3 people in the boat.

Can I get away with a 50,60 or 70 HP engine ( cheaper to buy, insure and run)? Or am I on a false economy? Ie will regret not going bigger at a later date.

The boat is in excellent condition so I am not looking for answers that recommend getting a completely different boat.

I would also be grateful for recommendations on engine suppliers in the Solent and good insurers.
 
Also remember if your going from 2 stroke to 4 then you will loose bottom end torque. I wouldnt go smaller if your going to 4 stroke & preferably go bigger if you can
 
I agree with the other replies. A 50-60-70hp 4 stroke will have dull performance on that boat. I've had/still have Yam 70 4 stroke, merc 90 2 stroke, 17 foot boats, smaller boats, etc, so speak from direct experience. You need a 90 2 stroke on that boat for lively performance, or 100hp 4 stroke imho
 
Would the prop also make a difference ?

When we had a bow-rider the advice was a 5 blade stainless would have a better initial pull, but lower top end, and vice versa for a 3 blade (or it could have been the other way around ?)

Insurance wise we have used Towergate (recommended by Birchells in Torquay), GJW (discounts for MDL berth holders) and latterly Y Yacht insurance (based on comments on this forum)
 
Andy Bav said:
Would the prop also make a difference ?

When we had a bow-rider the advice was a 5 blade stainless would have a better initial pull, but lower top end, and vice versa for a 3 blade (or it could have been the other way around ?)

Insurance wise we have used Towergate (recommended by Birchells in Torquay), GJW (discounts for MDL berth holders) and latterly Y Yacht insurance (based on comments on this forum)
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More blades have more bite for a better hole-shot but if you dont have the power to lay down then more blades would probably exacerbate a hole shot.
 
jfm said:
I agree with the other replies. A 50-60-70hp 4 stroke will have dull performance on that boat. I've had/still have Yam 70 4 stroke, merc 90 2 stroke, 17 foot boats, smaller boats, etc, so speak from direct experience. You need a 90 2 stroke on that boat for lively performance, or 100hp 4 stroke imho
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A couple of days ago. we tried with the Novurania (4.3m with 70Hp 4 stroke Yam).
My son managed to get up but complained that it didn't have enough power.
My son is starting to get a bit chubby but when we tried pulling a bigger guy it was impossible.

That said, our old little Walker Bay with the 40Hp seemed to do a better job.
I changed the prop on the walker bay to give it more power at lower revs so I was wondering if I should do the same for the Novurania.

So, all considered, I agree with JFM - it seems that you will need more than 70Hp
 
Yup. The 70 yam is gutless till the revs get high, but the novu 4.3m rib is a much smaller/lighter boat than OP’s 5.3m Grp boat.

I (being a heavy bloke) can get up on 2 skis behind the yam 70 Novu 4.3, with iirc a 14p prop rather than the factory 16p, but I can’t get up on one ski (deep water start). I got a skilled supermodel up on one ski (deep water start) this summer (and put up a YouTube of it for those who know my channel).
 
Hurricane said:
I changed the prop on the walker bay to give it more power at lower revs so I was wondering if I should do the same for the Novurania.
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Hi Mike,
Following Jfm's advice,
We have changed the prop, to a K-type 3blade 3-1/2"X14" (one step less pitch than the orriginal)
and this made a good overall improvement for towing or heavy loaded with ppl,
going on the plane is now effortless.
the little loss in topspeed is totally unimportant
can fully recommand the change
I assume you have the auto trimflaps ?
these are also needed on this Rib model, with the slightly heavy OB
 
BartW said:
Hi Mike,
Following Jfm's advice,
We have changed the prop, to a K-type 3blade 3-1/2"X14" (one step less pitch than the orriginal)
and this made a good overall improvement for towing or heavy loaded with ppl,
going on the plane is now effortless.
the little loss in topspeed is totally unimportant
can fully recommand the change
I assume you have the auto trimflaps ?
these are also needed on this Rib model, with the slightly heavy OB
Click to expand...

Thanks (and JFM)0
That is very useful information.
Probably too late for this season but I will put it on list for next year.
Thanks
 
jfm said:
the novu 4.3m rib is a much smaller/lighter boat than OP’s 5.3m Grp boat.
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Exactly.
If the boat can take 115hp as BruceK said, I wouldn't put anything less on her, for waterskiing. And possibly 2 stroke!
 
Also; make sure the engine can trim right in.

On my Merc 75 2 stroke, Fletcher recommended removing the stop bar to allow the engine to trim in further. (this was many years ago - 1994; don't know how newer outboards are set-up)
 
It'll depend how good the op is on the skis, someone good could probably get up with not much power, but someone less good will need all the power you can supply.

I used to(as a 17 year old) be able to ski behind an inflatable with a 25hp 2 stroke, when I was around 30 yo I could ski off a 50 hp yamaha 2 stroke on a 4 m inflatable. I like to think I could still (aged 46) ski with the 50hp now, but I won't get the chance to try.

Back to the op question, get as much power as you can afford, even if you don't need it to ski, you'll appreciate it anyway
 
julians said:
when I was around 30 yo I could ski off a 50 hp yamaha 2 stroke on a 4 m inflatable.
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You mean with 2 skis, don't you?
If you are also interested in slalom waterski, there's no way you could deep water start off any 50hp powered boat, and it ain't a matter of how good you are.
In my 30s, I did try monoski deep water start pulled by a 50hp (or possibly also 60, not sure) rib.
And I was fit enough to keep holding forever, but the boat simply couldn't gain enough speed!
Pro skiboats aren't powered by 300hp+ engines for nothing.
 
MapisM said:
You mean with 2 skis, don't you?
If you are also interested in slalom waterski, there's no way you could deep water start off any 50hp powered boat, and it ain't a matter of how good you are.
In my 30s, I did try monoski deep water start pulled by a 50hp (or possibly also 60, not sure) rib.
And I was fit enough to keep holding forever, but the boat simply couldn't gain enough speed!
Pro skiboats aren't powered by 300hp+ engines for nothing.
Click to expand...
Yup. Actually we did a Yam 70hp dock/jump start (as distinct from true deep water) with with Casper Lee who is 6foot 2 and not fat but a big guy 80kg, at 1:57 in this video. https://m.youtube.com/watch?v=OW0Ufh-J1gQ
I’m talking mono, throughout.
 
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MapisM said:
You mean with 2 skis, don't you?
If you are also interested in slalom waterski, there's no way you could deep water start off any 50hp powered boat, and it ain't a matter of how good you are.
In my 30s, I did try monoski deep water start pulled by a 50hp (or possibly also 60, not sure) rib.
And I was fit enough to keep holding forever, but the boat simply couldn't gain enough speed!
Pro skiboats aren't powered by 300hp+ engines for nothing.
Click to expand...

We used to start on 2 skis and then drop a ski once up to speed.
 
julians said:
We used to start on 2 skis and then drop a ski once up to speed.
Click to expand...
Been there, done that & got the T-shirt.
But I very much prefer (well, used to, 20Kg ago... :o) the mono rigged with two boots.
Which obviously restricts to deep water start.
 
We have a 3.8m rib with a 40 veto yamaha 2 stroke & I still occasionally ski behind it. I deep water start with both feet in the binders as opposed to trailing a foot. Boat is very light & I'm 6'4 but only about 13.5 stone, need a light driver & even lighter or no observer. You dont need massive hp to ski but the boat / engine combo has to be right
 
That's impressive, well done.
The 50 (60?) hp RIB I previously mentioned was actually a bit bigger (4.5m, IIRC), and my mate at the wheel was far from lightweight.
But we also had no observer, and in spite of that neither myself nor my mate (who was a terrific skier btw, capable of scoring 2 buoys @ 38 off) have never been able to deep water start with two boots behind that boat.
Maybe we were spoiled by the fact that we used to ski behind a Malibu of another friend of ours, which could have pulled out of the water a concrete block!
 
I learnt to deep water start behind a 50HP on a 15 foot speedboat; one foot in the bindings, the other trailing. It's a lot easier for the boat that way but possibly more difficult to learn.
I have also done a mono deep water start behind a 20HP on an 11 ft inflatable as a one off, just for the craic. I'm 5'6" though & was about 50kgs at the time.
Having said that; I've also skied behind a 200HP Yam Pro V that was pitched down for acceleration and nothing beats more horsepower.

To the OP: Get the biggest engine you can!
 
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