I/O (Sterndrive) Conversion to Outboards

Lou C

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My plan for that is to make it easier; next engine closed cooling & remote oil filter mount. These changes will eliminate the need for me to remove the rear seats & wood frame just to do an oil change & pull the block drain plugs.
And, what’s the biggest boat you can get that will be fast enough with a single engine? That would reduce the work by half. If I wind up ever doing what I said above it will reduce the time & work by about 75% and, the only other thing is pulling the outdrive which with the drive jack I have is easy.
While you can’t get this in new boats now I’d think a 26-28 footer with a 454/BIII or Volvo DP would fit the bill. Of course for me it has to be old enough for no Cat exhaust. The bigger boats have more room in the engine bay with a single engine it can be acceptable.
Outboards are great but keep in mind that they break too and we’re not fixing those in our driveway most times.
 

tpenfield

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Ted, for the $150k conversion, you could pay someone $5k per year to do the maintenance for the next 10 years and sell it to come out ahead.
I'm thinking the conversion to OB of my existing boat would be about $100K. (not $150K), regardless . . . it would be a whole lot of work and managing of logistics on my part. I'd rather turn my existing boat into $$$,$$$ and then break open my piggy bank and go from there.

Cruiser Yacht is willing to be helpful with a conversion. . .but I'm not sure what that would entail. If (big IF) they offered to do the conversion back at their factory, I might consider it. I know Formula was doing work of that sort years ago when there was a down-turn in the new boat market.
 

Scott Danforth

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I'd rather turn my existing boat into $$$,$$$ and then break open my piggy bank and go from there.
The simplest and fastest 3-step process works for converting anything

Step 1, sell what you have for a small pile of cash
Step 2, empty wallet on pile making the pile bigger
Step 3, buy what you want
 

Scott Danforth

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My plan for that is to make it easier; next engine closed cooling & remote oil filter mount. These changes will eliminate the need for me to remove the rear seats & wood frame just to do an oil change & pull the block drain plugs.
And, what’s the biggest boat you can get that will be fast enough with a single engine? That would reduce the work by half. If I wind up ever doing what I said above it will reduce the time & work by about 75% and, the only other thing is pulling the outdrive which with the drive jack I have is easy.
While you can’t get this in new boats now I’d think a 26-28 footer with a 454/BIII or Volvo DP would fit the bill. Of course for me it has to be old enough for no Cat exhaust. The bigger boats have more room in the engine bay with a single engine it can be acceptable.
Outboards are great but keep in mind that they break too and we’re not fixing those in our driveway most times.
Look for salt water boats that the owners left the manifolds go too long. I was looking at a 32 foot with twins that had two dead 8.1's. whole boat was being sold for $10k

Deck upholstery was starting to go. Was looking at about another $12-15k to get the boat water ready
 

tpenfield

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I joined up an OB conversion group on FB the other day. Not many members (300 ish), and it looks like the sweet spot for doing OB conversions is older boats, traditional transoms, and low tech controls.

Also added a boat (Sailfish) to my list of prospects.
  • CY 338 OB - Wicked pricey - probably too much.
  • Saxdor 320 GTO - Wicked expensive too.
  • BW 320 Vantage - Would be my favorite
  • Regal 33 OBX - My second favorite
  • Sea Ray 310 SLX OB - Smaller boat than my current, lots of seating, might not cost too much to swap-out.
  • Robalo R317 - Good seating layout, May not cost too much to swap out.
  • Sailfish 325 DC - Decent layout, lots of fold-down seating. More of an offshore hull. Less pricey than the others.
 

tpenfield

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Quick Update . . .

the Admiral wants to get an estimate of what it would cost to have a conversion of your current boat done. there are a couple boat yards in my area that do that sort of work. So, we'll see.

My guess is $100K+ . . .
 

Lou C

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My brother just traded his 2020 Chap 21’ I/O for a 2024 Chap 19’ outboard. Nice brand new no more I/O headaches!
 

Stinnett21

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My brother just traded his 2020 Chap 21’ I/O for a 2024 Chap 19’ outboard. Nice brand new no more I/O headaches!
I'm wanting to the same thing. My knees are telling me I need to stop crawling around in the back of this thing.
 

Lou C

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I've had a good run with mine but would I buy another, not for here I wouldn't, I would consider repowering it, but really the only reason to put up with I/Os here is if you want a cruiser type boat, that can be powered by a single engine, that has good engine access, and NO cat converter exhaust.
Smaller boats, in the range of 17-26' there is no advantage to I/Os any longer, not if you compare parts prices for what Mercury and Volvo charge for their modern I/Os. Yes old school ones were much cheaper to repower but that's not so true any more.
With my brother's boat, one episode of a mild overheat due to barnacles growing in the water intakes, was enough to turn him off to having one here moored in the salt water even though we fixed that in about 10 min with a coat hanger wire and gun brushes! I clean mine once a month.
 

thedinz

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The problems of I/Os in salt can’t be appreciated unless you’ve been maintaining one for some years. Moored boats you will get marine growth no matter what the anti fouling paints for alu just don’t work that well. Ted’s engines were closed cooled from the factory so that’s covered. No one here is buying sterndrives anymore. At the Nassau County Boat show (Long Island NY) I saw a few inboard boats and I/Os but the great majority are outboards. The coastal salt water market has totally shifted.
As for me as much as I love Chevy small blocks here in the salt pond for the future outboard only. I’ll take a Chevy in a hot rod in a boat the old school mechanics call I/Os double trouble lol. I’ve done really well with mine but it took hrs of regular maintenance EVERY year!
This is why i keep it in fresh water only, not the only reason but a main reason for sure. My boat has never seen salt, and never will.
 

Lou C

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Well all we have here is coastal salt water. They can be made to last as I have done, but it takes a lot of work. As far as extra maintenance & repairs in salt water, what I’ve found it’s mostly the anti fouling of the outdrive & transom mount. Not many actual repairs needed, I just resealed the trim rams this year, the biggest thing is exhaust system replacements. One nice thing about coastal salt water is we never have droughts or low water levels. Always plenty of mostly deep water…
 
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tpenfield

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My brother just traded his 2020 Chap 21’ I/O for a 2024 Chap 19’ outboard. Nice brand new no more I/O headaches!
Hi @Lou C Did your brother have to take a bath on the re-sale value of the I/O? or was it OK?

I think I/O's are quite fine for the lakes, but every year there are fewer in the ocean. In my harbor, out of approximately 100 boats, only about 5-6 are I/O's . . . in the past it was more like 10-15%.

I probably won't do the conversion of my boat even if I can get a price estimate, because there are some decent day boats available with outboards, and the total outlay will probably be less $$$$$
 

tpenfield

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Quick Update . . .

I have not gotten the local shop to respond to my inquiry about a OB conversion, so maybe the easiest thing is going to be the sell/buy route.

The Admiral nixed the more fishing style boats, so we are down to Sea Ray and Regal, and maybe the Boston Whaler as the likely contenders.

I have posted a couple of Ads to see if I get any bites on my boat before the season ends.
 

Scott06

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Quick Update . . .

I have not gotten the local shop to respond to my inquiry about a OB conversion, so maybe the easiest thing is going to be the sell/buy route.

The Admiral nixed the more fishing style boats, so we are down to Sea Ray and Regal, and maybe the Boston Whaler as the likely contenders.

I have posted a couple of Ads to see if I get any bites on my boat before the season ends.
Much smaller boats that I have had, but I have been very happy with the two Sea Rays we have had over the last 30 years- 1991 170 BR, and currently 2004 200 sport. On the 04 I had the first non-human stupidity induced fabric tears on back bench. Gel coat still looks good with occasional buff and wax (2 x in 9 yrs)

Held up well and solidly built.

I do understand the seasonal PM/ winterizing and saltwater corrosion advantage of OB's but looking under any of the newer big higher HP OB cowl it may be a false economy on maintenance savings. If i recall Muc chimed in on a thread stating how extended warranty costs on OBs were double stern drives or double what they used to be for OBs. Suspect there is no truly free lunch...we just use our swim platform too much to give it up.
 
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Lou C

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There is truly no free lunch, one thing to keep in mind is that in the last 15 years engine tech on sterndrives has become much more complex and expensive, parts cost isn't much less than outboards, and due to ridiculous designs coming out of the sport boat makers, access is worse than ever.
I/Os made sense and were tolerable for me when:
1)outboards were loud, smokey and not too reliable
2)sterndrives had simple carbureted engines, cheap & simple to repair
3)sport boat design lent itself to more accessible engine compartments, without "improvements" like 'glassed in rear seating areas, or walk throughs that make the engine compartment even smaller (and the geniuses manage to put it on the side where the small block Chevrolet starter is, making that job nearly impossible).
The boat that my brother just traded, was a really nice running boat but a future maintenance nightmare, and I told him so. Having to pull the engine because Chapparal can't design it to allow you to change a starter, unclog Merc's single point drain, or God forbid, change a steering actuator, is a no-sale for me.
We are going to water test the Chap he bought with the outboard out on the Great South Bay this weekend, should be fun.
 

dingbat

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I do understand the seasonal PM/ winterizing and saltwater corrosion advantage of OB's but looking under any of the newer big higher HP OB cowl it may be a false economy on maintenance savings. If i recall Muc chimed in on a thread stating how extended warranty costs on OBs were double stern drives or double what they used to be for OBs.
Prepaid Service agreements and extended warranties are cash cows for Service departments....lol

Buying either is foolish at so many levels....
 

tpenfield

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OB's are not going to be 'easy street' by any means, after all it is still a boat.

More boats are coming out with decent swim platform designs around outboards, whereas 10 years ago it was pretty much non-existent. For me it has the following advantages:
  • no anti-fouling on the lower unit . . . (prop efficiency)
  • although the engines would still need work, stuff should be more accessible.
  • get closer to shore . . . traverse skinnier water.
I've had Sterndrives (I/O) for 20 years. but . . . I think my needs are changing in the direction of OB's
 
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