Keith-i
Well-known member
It’s to counteract the torque of the engine not to affect any direction of travel. The small trim tab on the anti-ventilation plate deals with the latter.
New build Sanlorenzo SL96A 2024
- Thread starter jfm
- Start date
julians
Well-known member
Mercury has the same on the verado's. It actually works surprisingly well for wakeboarding/waterskiing if you have someone relatively inexperienced driving.
jfm
Well-known member
With RH (clockwise) prop the hull is being forced anticlockwise, Newtonianly. Offsetting the engine to the right makes the hull more resistant to being forced anticlockwise, ie the hull is stiffer when you twist it anticlockwise than clockwise. There is more hull to the left of the engine than the right.
This is universal thinking - every fast outboard I've ever owned has been nudged to the right.
The decals are not custom but they are Yam's new look just for the optioned-up SBW version of their big engines. The normal engines get stickers/decals with a swoosh as before; the SBW engines get this raised/solid lettering and no swoosh decal. Obviously the white pearlescent paint is a factory option.
Elessar
Well-known member
Fair enough. Every day a school day.
I’d have never have supposed that. Obviously if you offset more to the right the boat will turn left (as evidenced by a duo prop twin engined boat with just the right engine in gear)
So I’d never had guessed that a small offset has precisely the opposite effect.
I’ve not really any experience of fast single engined boats.
John100156
Well-known member
That's very interesting, I understand the logic. I suppose there is no need to mathematically work out the vector forces as an uneven load on the boat etc could also affect it to some extent. Just move it a bit and evaluate the end result.
So why don't they use some form of counter rotating duo-prop on an engine of this size? Surely that would reduce prop walk, not sure about the torque issue? It does look really smart though white....
So why don't they use some form of counter rotating duo-prop on an engine of this size? Surely that would reduce prop walk, not sure about the torque issue? It does look really smart though white....
jfm
Well-known member
You can get counter rotating duo-prop outboards John, though there aren't many. IIRC, Suzuki do a couple. They haven't really caught on, and I suspect the reason is that they are a solution looking for a problem, and they add several kilos. Normal outboards work just fine for this type of boat.
ontheplane
Well-known member
Can I ask a blitheringly stupid question?
On my old boats (think 70's 80's) to engage gear, you had to lift a lever, and THEN move the shift into forward or reverse, otherwise the engine was "locked" in neutral.
I get the "throttle only" button on the Suzuki / Yam - but does this mean that unless you press this - moving the shift lever just engages drive and throttle?
That sounds mightily dangerous - as someone could just slip, put out their hand and unleash all 300hp in one go........
I suspect I am misunderstanding though as that doesn't sound right.....
Pic of what I mean
On my old boats (think 70's 80's) to engage gear, you had to lift a lever, and THEN move the shift into forward or reverse, otherwise the engine was "locked" in neutral.
I get the "throttle only" button on the Suzuki / Yam - but does this mean that unless you press this - moving the shift lever just engages drive and throttle?
That sounds mightily dangerous - as someone could just slip, put out their hand and unleash all 300hp in one go........
I suspect I am misunderstanding though as that doesn't sound right.....
Pic of what I mean
ontheplane
Well-known member
Also - what made you choose the Yamaha against say a Suzuki 325 or 350 with contra rotating props which I understand are also excellent and around £4-6k cheaper (although I realise cost isn't the main driver here).
jakew009
Well-known member
Yes, that is basically correct. With the Mercury digital throttles, there is no safety mechanism.
The neutral button is pretty dangerous as well, because after a few seconds at idle it times out and goes back into gear
ontheplane
Well-known member
jeees.....
That sounds absurd! So anyone falling onto the levers these days can make the boat shoot off??
I'd be wanting the engine totally off as well in that situation if I (or anyone) was in the water.....
That sounds absurd! So anyone falling onto the levers these days can make the boat shoot off??
I'd be wanting the engine totally off as well in that situation if I (or anyone) was in the water.....
jfm
Well-known member
Not a stupid question at all. Basically the big manufacturers have the mechanical lock in your picture for their small engines (up to maybe 100hp) and no mechanical lock for their bigger fly-by-wire engines. It's been that way for perhaps 10+ years. I don't like it either, and I much prefer the mechanical lock, but this is what the market has demanded, it seems.
You just cant buy a 300hp any more that has a mechanical lock. This is part of the reason I insist the engine is turned off when approaching swimmers. I'm fine with wearing out the starter motor - they are cheap as chips compared with legs and arms.
jfm
Well-known member
No great scientific reason. I've never loved Suzuki outboards tbh and have had (since 12yo) Mercury and Yamaha, and see them as "the best". I realise that's subjective of course. I see the duo prop as a solution looking for a problem, and Suzuki are very late to the party with integrated power steering - first shipments happening now whereas Yamaha have nearly 2 years and thousands in service.
Integrated steering is a very important part of the spec because it gives autopilot and heading hold functionality. Suzuki are doing it by hydraulic rack+pinion (with, I think, an external hydraulic pump and visible hoses, urgh) whereas Yamaha and Mercury are using a 100% integrated electrically driven leadscrew, which is much better - to be frank Suzuki's product here feels very inferior imho.
Finally the cheaper price of Suzukis is more off-putting than attractive, imho. All a bit subjective of course and we are choosing between several excellent engines here.
ontheplane
Well-known member
I have to concurr the only Yamaha outboards I've owned have been absolutely, utterly and 100 % reliable - even at 20-30 years old!
jointventureII
Active member
There is a chase boat in our marina at the moment with 5,500 hours on a pair of Yamahas, according to the captain they've not missed a beat since new. They have, of course, followed the maintenance schedule to the letter but that's still pretty good going.
MapisM
Well-known member
Do you possibly remember the model?
PowerYachtBlog
Well-known member
Up until 2010, Yamaha was the best, though in the last decade they are not so good as they used to be. Above 200hp Mercury is the king, also as what most reviews say on the US forums.
The Yamaha 425hp has had its way sort of issues over 500 hours for example. And 500 hours in the US market might just be a couple of seasons.
jointventureII
Active member
I don't but as PYB says, they're of the older generation 4-strokes, would be from somewhere between 2005-2010.
Mr Googler
Well-known member
Any mother ship developments J?
jfm
Well-known member
Plenty, but I don't have pictures atm. I'm at the factory in Tuscany this coming Monday for a good look, so will report back after that. The Ribeye is also progressing fast.
In the background I have zillions of emails - there's an email exchange with dealer/factory perhaps every second day. Building a Sanlorenzo doesn't have to be like that, but for a customer who wants to know/check/decide/approve every detail, they are happy to work this way. Would be too nerdy and detailed to relay all email exchanges on here, but as an example I received today (a) pictures of the marble slabs that have been put to one side for me to choose from on Monday, and (b) a set of 3d models/renders showing alternative positions for exactly there the chocks will be mounted. for those occasions when the Williams 435 tender isn't in the garage .
There are also lots of things that have been going on in the background, and I'm doing them early because of long lead times. Eg in the last month I have placed orders for cutlery, crockery, glasses (I'm not using the posh names which I think are flatware, dinnerware and stemware
) and towels + bedlinens will be coming soon. This is all quite hard work and I gasp at the cost if you choose ok-ish stuff in these quantities, but I'm pressing on. I also ordered the "Match" name for the transom, from Yachtlite in Germany, and the floating dock for the Ribeye in Antibes which is a June 2023 project. Loads of little things to do.The marbled areas GA, and the tender 3D models emailed to me this morning by Sanlorenzo are below, just to give a flavour. In the marble plan, the 3 colours denote the 3 different marbles that will be used on the boat. The galley will have Dekton rather than marble, and the crew areas and flybridge bar units will have Corian, so they are not on this GA. The marble will come from the Carrara mountains, a few miles inland the boat building towns in Tuscany. In the tender renders, the bottom right hand corner is one we will use.
I'll write some more next week after visiting the factory.
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jfm
Well-known member
I don't buy any of that - its just broker bar talk, not expert talk. What happened in 2010 to make Mercury better or Yamaha worse? Nothing.
In any case/better worse is a model-by-model thing, not a brand thing. Most of the manufacturers have a couple of suboptimal engines in their range.
Focussing on this size of engine, The 6 cyl mercury S/charged Verados were 2004-2018, so nothing big happened in 2010 to make them better. The current (beautiful) V8 Verados were launched 2018. I wouldn't rate the older 6 cly Verados as a thing you would choose if looking to buy the best, but I would rate the new v8 Verado.
With Yamaha, the current series of 4.2 litres V6 (like on my 300hp) was launched in 2010, though derived from the earlier V6 form around 2002, which I guess is what JVII has.
Verado V8 (and V10+v12) is a beautiful thing and at least as good as and probably a bit better than Yamaha v6/v8, though that's comparing incredibly good with even more incredibly good. As I customer, I was focussed on guaranteed delivery date of a white-painted engine, Yamaha's better fly-by-wire steering (mercury's is slightly disappointing), and the fact I have a great dealer locally, so I chose Yamaha, but could easily have chosen Verado - it was a very fine choice with no wrong answer.