Mangusta 72 - Arnesons

On the lake we were on, it wasn't just normal deterioration. Apparently, the Mercruiser bellows were a favorite of muskrats along with the styrofoam under docks. I wasn't aware this was an issue with Arnesons.

In warm water, nearly every year service. Careful dive service every month.
No they can live two years if you change the anodes every year.
The anodes are the big protection to the joints, which is the delicate area of the surface drives.

Oh, boots, bellows. Big black rubber (expensive) things.[/QUOTE]
Surface drive bellows serve four or more years. What double there lifespan is also to make a diving material cloth around them.

Also unlike stern drives, surface drives below are protecting the cross shaft. Surface drives are like shafts in all other aspects, the gearbox is inside the engine room with the engine.

If the below fails on a stern drive boat 1. you would be sinking, and 2 you have water ingress in your gearbox. Two headaches for now and then.

All the above is the same for jets with the exception that they say are more delicate anode wise in the shaft area and if you hit them they cost a lot more to fix then surface drives.

So, you have had boats with Arneson Drives that you have had to replace the boots every year? By the way ... the only function of the boots is to provide protection and prevent marine growth on the ball on the thrust tube. They are not seals for the oil/sea interface.

All the above is the same for jets with the exception that they say are more delicate anode wise in the shaft area and if you hit them they cost a lot more to fix then surface drives.[/QUOTE]

I'm going to have to disagree with you on this one, in that yes if you physically hit the external portion of the jet drive, which in this case for a large Mangusta (RR / Kamewa Jets) you will be hitting the Reverse Clam Shell and probably going to damage the reverse cylinders and steering cylinder. On the AB Yachts you will be hitting the (MJP Jets) that would damage the same things. All the externals on the MJP Jets are Duplex Stainless Steel, so if you damage those, then you will more than likely have quite a bit of damage to the hull as well. However, with the exception of changing the anodes on a regular basis on the waterjets themselves, on the larger jets (600MM diameter) and larger, there are only very few scheduled maintenance items that need to be tended to.

I've spoken to CaptKilbride about waterjets in the past and have operated lots of AB Yachts with jets (78' 92' and 116'), as well as commercial boats with MJP, RR, Hamilton, and Doen Jets and yes they have their quirks to them, but so do Surface Drives. The Sunseeker that I used to operate had Surface Drives on it and I loved it for going fast and getting to my destination for the owner and guests, but I also hated maneuvering into a tight slip with them as well as the maintenance that incurred with them. I'm an advocate of having the correct application for the machinery. Surface Drives for going fast and getting to where you want. Props for durability and longevity and the "bite" that it gives when you go into gear, and Jets for maneuverability and longevity as well as speeds. Again, just my 2 cents and I'm by no means an expert.

I'm sure the frequency of replacing the boots varies significantly by the water the boat is kept in and it's use. It sure does with stern drives. We lived on a lake with two major issues for stern drives. First, the chemical content of the lake was very high (natural chemicals flowing out of the mountains and the rocks there) which made outdrives look and act like they'd been in salt water, second the aforementioned muskrats.

We rarely see fancy drive set-ups in this area.
It was long (LONG) ago while working on an old triple Magnum with original Arnesons that I learned enough to be dangerous.
The chemicals in the water behind Blount Island worked on the bellows and some hoses just as fast as the barnacles.

Running out the river at speed sure was fun.
I remember, I did not like the drives during the pitching going out the Mayport / StJohns inlet. We learned to just hold on and not slow down to much.
I didn't like that either.
Slow operation coming back with tall following sea was typical. It was safer that trying to come in fast and not able to see ahead or under the bow.

Off shore Jax for fishing or diving was a PIA.

I'm sure all of the new stuff is all new and better. Boats are probably designed to work better with this drive system these days.

I just remember my simple understanding of that system and how it handled.
For myself, I can not afford the fuel to go fast. I'll never need or desire a surface drive system.

No one gets a Magnum for fishing. lol
They're for going places fast.

It did that fairly well (going fast) but here is south GA, we have to have multi mission boats that are exposed to multiple conditions. Deep, shallow, fast, slow zones, JAX inlet, StAug & StMArys inlet Way up the river (south) and all on a red neck budget. Fish, swim and dive anywhere.
That boat boat only lasted a few years up here. Went north I think.

As I said above ; Boats are probably designed to work better with this drive system these days.
If not, gonna be a PIA having fun on the island banks. You just going to fast to get there and come back or enjoy the waters?

I'm sorry, I'm not meaning to be negative thru all this, I managed an old 44 Striker and had a blast on her in the islands.
I can't imagine moving up from a big Striker to something fancy and cant get in/out the water without spilling my rum...
And, I'll always be biased against them (Arneson type drives).

Not my preference either. I like jets which many people hate.

Huckins has tried some surface drives, Then went to the jets. A few have been thru here (jets) and many original owners are still happy.
The last build was Cummins/Zeus.
IMO; ugly boat but customers are very happy.

I'm not so sure about the cons typically referred to for ASDs and slow speed operation. I did an approx 800NM trip recently in an M91 powered Mangusta 80 that forum member Liam introduced me to (and that I ended up purchasing) and although we cruised most of the time starting at 28/32 with full fuel tanks, to end up at 37/38 when lighter, at a given point, we also had to cruise for about two hours at 14kts due to pretty high and long waves. it took some careful adjustment of the throttles and trim, but eventually all turbos were on green, the numbers were good, and we just watched it. It was bit long I admit though. It was a long trip and everybody wanted to make it fast.

As to helm input, the boat requires constant attention as it is pretty much always moving away from the bearing, no matter what speed you are sailing at. Other Mangusta 80 skippers recommended simply to avoid using the AP because of its erratic atitude (this is a 2003 vintage). Just make sure somebody is on it all the time. And we even sailed during more than 3 hours at 36/38 kts with FORCE 5 from astern BTW. Nothing bad to report. Surfing in true fact. Big boat for that kind of thing though, but it gets there.

During the sea trial, with less than perfect seas, we managed 43kts but then we got a high oil temp warning and had to reduce speed. I have changed the oil heat exchanger since then. I am confident it will exceed that.

On the maintenance, aside from a Steering hydraulic leak inside the boat, and both steering cylinders servicing, (which probably could have happened with a Jet drive) so far, so good. Let's see with time.

So I would not keep from buying a Mangusta 72 because it has ASDs and I don't want to sail at 30+.

My $0.02

Good information. What kind of autopilot do you have? I'm wondering how others have found autopilots with ASD's.

The AP CDU is a Simrad and I don't have the reference off the top of my head. The hydraulic system is a BCS / Arneson SI 315. I would guess all these boats would have the same system. Maybe Pershings as well.

I assume you've tried all the adjustment possibilities on the Simrad, changing sensitivity for the various conditions? While I still always believe in someone at the helm, I've not found the situation yet in which an Autopilot couldn't keep a good line. Now, in winding canals and rivers, it's a different story.

The issue I've been told is that it can veer suddenly right or left. No matter what speed you are cruising at. We had a hard time getting this one to work because the boat sat for several years prior to me purchasing it, but with that kind of information, I preferred standing at the wheel while the ferry skipper preferred to use the tiller. An Arneson rep told me later to avoid the tiller when cruising because of the "open or closed" nature of the valves actuation, while the wheel is much more progressive on the lines.

This is good info.
When you can, sure could use the AP, control box and pump model you are using and more examples.
As noted above, years ago was my only experience with these drives (on a different boat entirely) and lots of designs have changed.
I'm a big Simrad fan. Just want to learn more.
Thx, rc

While I do believe in always having someone at the helm, I also think you got poor information. Perhaps accurate on an old, poorly serviced, poorly functioning autopilot, but I've seen captains who just really didn't know the capabilities of their autopilot or how to adjust them. I don't know how much veering he was referring to but it shouldn't be more than a little and immediately followed by a correction, not something like rocketing you into a bank. Now, also hands on wheel for all bridges and things of that nature. I'd get out and practice with my autopilot, make adjustments and see what they do. Perhaps update.

I'll get more on it later.

The first Skipper to tell me about this, has been a skipper on a 2004 Mangusta 80 from new, and is also a partner to a shipyard. He has all the resources required to make a well informed statement. His Mangusta is impeccable. Also, he mentioned clearly that it can veer 90 degrees when at 35 kts. Then my ferry skipper, who recovers boats for a repo business and has a lot of experience with various types of motor yachts sailing under dire technical conditions, concurred. During this trip that lasted nearly one month, mostly due to weather, we had many things to worry about, and the AP came in as a low priority item. Nevertheless, the skipper managed to get it going at some point, and it operated well for a while, until it stopped correcting the drift. But as I said, I took no real interest as other issues were of bigger concern to me and we did several sectors of approx 5 hours demonstrating this is a far as we were willing to go on a single day. So no real need for AP.