Advice Needed: Cruiser Yacht with Outboards

[bishbash89]

Guys,

Apologies in advance if I'm not using the correct terminology - I'm completely new to the world of boating. I'm planning to purchase a new boat soon, and I've found a Cruiser Yacht 280 cxi (2007 model) that's had a conversion from inboard engines to outboard engines done - 2 x 200 Yamaha 2017 engines (20 hours running). I love the boat, it's well maintained and I'm getting the local Yamaha team to inspect the engines.*

One concern was raised by a friend is that due to the change in weight/centre of gravity shift, the boat may not run as well on the water and may experience "bouncing" - is this common for boats converted to outboards?*

I'd like anyone with experience of this kind of conversion to give me some advice as to what kind of problems I should look out for (detailed explanation would be useful - I have no practical experience), what issues I may face and whether there will be any impact on handling, performance, efficiency, etc.?

I'm planning to go for a drive/sail/cruise (not sure of the correct term here) on Thursday, so any advice you could give me before then would be greatly appreciated.

Let me know if you need more details.

Thanks,

​​​​​​​Bish

[Bullshooter]

Bish,

Since you said that you were completely new to the world of boating, you should do yourself a favor and get some instruction and experience before buying a boat and roaring off.

If you go on the test drive, use it to see if the boat is in balance, and learn to understand that as you trim the motors up, the "porpoise-ing will generally get worse, and if you trim them all the way down, it may stop the bouncing, but the wheel may pull to the side. Sometimes installation of trim tabs on the stern are necessary to get the boat to trim properly.

Don't buy the boat. I personally believe you need to gain experience with a seasoned boat owner, one way or another, before owning one. That is actually my best advice.

Probably not what you want to hear, but I am just trying to be helpful.

[bishbash89]

Bullshooter,

Thanks for the reply mate. I appreciate the advice, but I've struggled to find someone who has the time and/or experience to give me tutoring. My plan was to buy a boat and use that as a way to learn - there are instructors who will give you tutelage on your own boat readily available, hence the need to find something that won't give me too many headaches from the start - I appreciate boats in general can be a headache but some more than others.

So despite the limitations, I would still be looking to buy, hence the need for advice as to what kind of issues I'd face from a converted boat.

Thanks,

[bishbash89]

I should also mention, I'm a British expat living in the Middle East where there is no legal requirement to have any formal training or qualifications to own/run a boat, hence the lack of professional support in my area.

I'm sure I could find plenty of local fishermen to train me, but I doubt it would hold up to any international standard of sailing.

[Lake-Effect]

Originally Posted by bishbash89

I've found a Cruiser Yacht 280 cxi (2007 model) that's had a conversion from inboard engines to outboard engines done - 2 x 200 Yamaha 2017 engines (20 hours running)

I don't have a whole lot of experience with larger motorboats and this sort of conversion, but the above is a whole set of red flags for me:

• Why was it converted to outboards? Enginies/trannies blowed up? Was the boat sunk? Why weren't the engines just repaired/replaced?
• Was the conversion professionally done?
• Why is the boat for sale so soon after this conversion? possible answers:
  • the boat was sunk or otherwise totalled and this is a quick patch-job to flip it
  • the conversion is less than successful and the owner is hoping to unload it

I would be very wary of this one.

[bishbash89]

Hi,

To answer the question about the inboard motor not being replaced - where I live, technical capabilities are limited and getting servicing done on inboard motors is a real struggle, and very expensive. The vast majority of boats (fishing and pleasure) are bought either outboard or retrofitted to outboard. Aside from your super-yachts, I cant remember seeing an inboard engine for a long time being used.

Luckily I know a few guys from the marina where its stored - I live on an very small island, so everyone knows everyone else, and they havent mentioned anything like that but I'll be sure to check it out. It was trailer loaded when I went to view and the hull looked to be in great condition, although I'm not sure if I'd spot a repaired hull after it's been fixed and painted.

I too have concerns over the relatively new age of the engines, so that's something I will follow up on with the broker.

Thanks for the feedback.

[Jim Cate]

I'm out of my league here, but I would be extremely suspicious of such a conversion. Two 200 hp outboards is one hell of a lot of weight and power to be hung off the stern of a boat that was not designed for such loads. Issues with structural integrity and with handling at speed are not trivial... in fact can be life threatening, especially in the hands of a novice operator.

I sure as hell wouldn't touch it, and I've got a lot of years of experience.

Jim

[a64pilot]

It’s actually not all that uncommon, I’ve seen Sportfishermen converted with several as in say four 300 HP Yamaha’s on the back.
I often wondered why as those motors go for about $30,000 ea, for $120,000 I figure you could have any kind of inboard you wanted.

The other day in Vero Beach we were passed by boat that I think was being demonstrated, it had four 425 HP Yamaha’s, a new boat that was built for outboards.
The 425 I think goes for about $45,000 each, times four and one wonders at what point do outboards not make sense?

I don’t think the OP is using cruiser the same as we do.

[Jim Cate]

Originally Posted by a64pilot

It’s actually not all that uncommon, I’ve seen Sportfishermen converted with several as in say four 300 HP Yamaha’s on the back.
I often wondered why as those motors go for about $30,000 ea, for $120,000 I figure you could have any kind of inboard you wanted.

The other day in Vero Beach we were passed by boat that I think was being demonstrated, it had four 425 HP Yamaha’s, a new boat that was built for outboards.
The 425 I think goes for about $45,000 each, times four and one wonders at what point do outboards not make sense?

I don’t think the OP is using cruiser the same as we do.

Interesting!

But I'd still think that major structural changes woulld be needed to accommodate 400 hp worth of thrust on what used to be a swim platform kinda hull. I admit to lack of knowledge about this sort of vessel, and perhaps am out of line!

As to the mounting of >1000 hp worth of outboards on the back of smallish boats (seen here in Oz both in the private and LEO sectors), I suspect it is often an expression of "my pee-pee is bigger than your pee-pee", not of great engineering.

Jim

[a64pilot]

I don’t know how they do it, nor do I know how the hull is ballasted, but the one or two that I have seen that were done in Panama City seems to be done well, with the hull sitting on it’s proper water line.
Pretty sure they were done at Miller Marine, but not certain.

The outboard thing is just pure nuts. Used to be an outboard made sense cause they didn’t take up any room in the boat, but mostly because they were lightweight and inexpensive.

Yamaha’s new 425 is a 350 cu in 1000 lb V8 and $45,000 ea. That’s nuts

I figure with inboards it’s not obvious how much you have spent and how much power you have, with outboards its out there for everyone to see. Surely that’s what is driving this?

[bishbash89]

Originally Posted by a64pilot

It’s actually not all that uncommon, I’ve seen Sportfishermen converted with several as in say four 300 HP Yamaha’s on the back.
I often wondered why as those motors go for about $30,000 ea, for $120,000 I figure you could have any kind of inboard you wanted.

The other day in Vero Beach we were passed by boat that I think was being demonstrated, it had four 425 HP Yamaha’s, a new boat that was built for outboards.
The 425 I think goes for about $45,000 each, times four and one wonders at what point do outboards not make sense?

I don’t think the OP is using cruiser the same as we do.

I agree that most boats are completely overpowered, however, people here have more money than sense, unfortunately.

Using the cruiser the same as you? No idea - how do you use yours? My situation is that I'm not interested in achieving the fasted possible speed - I want to enjoy the journey! I'm not interested in the HP, so long as it's sufficient to get me from point A to point B with as little fuss or drama as possible.

Regarding the engines, they are what comes with the boat and they are in good condition, under warranty and have very little hours. This is one of the reasons I'm interested in the boat, as a lot of the engines I've encountered whilst searching for a boat have not been maintained well. Yes, there are some questions to be had about the performance - hence my post here.

As to being overpowered - 450hp is the output the original internal engine would have produced - so if anything, I'm underpowered vs the original spec.

I appreciate everyone has their concerns, but in reality, I'll be in relatively shallow waters 3-8meters around the island, the majority of the time will be spent island hopping, with the further island 20 miles out. My needs are purely for pleasure - taking friends out to a nice sandbank or island, maybe the occasional overnight stay anchored in the shallows and maybe some fishing while I'm out and about.

I have zero interest in how the boat looks nor how big my engines are (seriously boys?!).
I don't anticipate venturing out into rough seas therefore how much of an impact, based on my activities, is there likely to be when it comes to having a boat with an outboard conversion and the effects a shift in weight/COG will have on handling? If weight is the issue, then I assume I could load another water tank where the inboard used to be to help with balancing? I've seen others do something similar to help with this.

[AKA-None]

The real question is will the transom hold up over time with those engines?

[bishbash89]

Originally Posted by AKA-None

The real question is will the transom hold up over time with those engines?

How would you test this? I assume you can brace/support the transom in ways in which to support the engine load?

[ArmyDaveNY]

Originally Posted by bishbash89

How would you test this? I assume you can brace/support the transom in ways in which to support the engine load?

Perhaps you could temporarily mount a camera on the transom and film the entire journey. When you return, play the film back at an accelerated rate and look for movement. I think that you are unlikely to see any movement at normal speed but at a higher rate you would see any movement.

[coastalexplorer]

You have written not intending to take the boat out in rough seas....Only used in shallows 3 to 8 meters?



I see a contradiction here! As waves roll around the world, The water gets more rough and violent as the distance from the surface to the bottom decreases causing less recovery time between waves in shallow water,