I/O (Sterndrive) Conversion to Outboards

[Lou C]

Well the way it all fits together a bellows leak will let some water in but not much remember there is (or should be) a seal behind the gimble bearing. So if that seal is there a bellows leak prob won’t sink the boat but sure it will ruin the gimble & ujoints). That Alpha shift cable bellows on the other hand can let in enough water to sink the boat if unattended. The OMC/Volvo shift cable tube seems like a better design. Never had a leak there on mine. Did have a leaky D/S bellows like 20 years ago did not sink boat but had to replace the gimble.

 

[Chris1956]

The rubber bellows are real thick. They get real crusty and cracked when they need to be replaced, but they usually don't leak. You should run a hand over them every season. It will be obvious when they need replacement. But you gotta look.

 

[tpenfield]

Another thing I always worried about was if a bellow springs a big leak, you have a big hole in the back of your boat below the waterline!

Yes, at that point, I would not be doing a conversion . . . it would be new boat time.

 

[Lou C]

It’s a misconception that the D/S bellows will sink the boat; as long as that seal is in place it will be a small slow leak. What will is that infernal Merc shift cable bellows! I never liked that design & think the OMC/Volvo shift cable tube is safer. When OMC came out with the Cobra they tried to improve on the Alpha drive by changing that & putting the impeller in a very easy to service spot at the end of the upper gear housing. Too bad the company was so mis managed because the engineers did a good job there and Volvo copied that and still uses that design….

 

[Scott Danforth]

Ted, you could always swap the 350 HP 6.2 seacore motors for 430 HP 6.2 LT motors for a lot less than an OB conversion

 

[cyclops222]

Ever THINK of removing a big hp engine cover in slightly rough water / waves ?

 

[KJM]

Ever THINK of removing a big hp engine cover in slightly rough water / waves ?

I guess thats where the second engine comes in, it gets you home, then you play with the faulty one.

 

[Lou C]

There are several “ifs” that would have maintained the popularity of I/Os vs outboards:
If (mod edit) inboards (didn't have) expensive potentially dangerous cat exhaust
If boat companies would design the engine space for easy access
If there were better/more effective anti fouling paints for aluminum
Etc.
I still say that the basic GM marine engine design in many ways is more practical than outboards (simpler design, cheaper parts, can be fully closed cooled).
Outboards can’t be closed cooled & they can be prone to water intrusion just like inboards; with the exhaust & cooling water passing thru the oil pan in some designs.
It’s the add ons & installation that causes the problems
On my brother’s 2020 Chapparal with the Merc 4.5 200 hp (very pleasant to drive), the engine access is so tight that if you had to replace a starter, steering actuator or unclog the easy drain you’d have a real headache on your hands.
The lesson of modern economics is that people will pay A LOT for convenience! That’s a big part of the attraction of outboards…

 

[tpenfield]

Weighing my options . . . If the cost of a conversion rivals the cost of a sell/buy, then sell/buy may be the way to go. Kind of depends on a bunch of variables.

 

[KJM]

Weighing my options . . . If the cost of a conversion rivals the cost of a sell/buy, then sell/buy may be the way to go. Kind of depends on a bunch of variables.

I think I'd buy/sell if I could swing it money wise. Once you start a conversion you will lose big on any resale value and you might not even like the result.....

 

[Lou C]

Those are valid concerns, for sure…money invested vs what you could sell it for & how well it performs. I followed a few of these conversions on the hull truth and the people who did them were happy with the result & performance but the cost is very high esp with a twin engine set up…

 

[cyclops222]

Lets cut out all the lies about the goodies of outboards being thought of before their birth. The big ones HAVE to be worked on in a expensive marina. With Fork Lift trucks.

 

[Lou C]

Well other than routine maintenance, very few people are doing major repairs on them. Partly due to extremely high parts cost, and also complexity. It's not like pulling the heads off a small block Chevy, that's for sure. Also, when they start to corrode on the block deck surface, or same place on the cyl head, it is very difficult to get a head gasket to seal again. A lot depends on the salinity of water where the boat is used. A closed cooled inboard is much better in that regard, as long as you don't neglect the exhaust system.
However, I do know some very accomplished DIY guys who have done midsections/oil pans on Yamaha 250s etc. They have hoists, and a full set of tools.

 

[cyclops222]

True There are Marine Motorheads.

 

[Lou C]

Yes they are!
As for me if this boat stays in reasonably good shape, I may just keep it and repower it when necessary, I figure if I'm lucky I got about maybe 5 more years of boating that I can do. So, not really worth spending $45-$50 K on a new or newer outboard boat. Repower = 1/10th the cost of buying new lol.

 

[Scott06]

Fair question. I am getting tired of keeping up with I/O's in the salt water (I think @Lou C can relate). I can do it, but my preference would be to have outboards.

I have considered getting a different boat that has outboards, but none that I've found have a layout as good as what I have, and/or would cost a whole lot more than doing a conversion.

So, I like the boat, not in love with the engines.

I think some of the maintenance advantage of OB's is perceived. yes the yearly items are easier but if you really need to get into some of the parts on the newer higher HP OB's willing to bet you will be cussing just the same.

For me personally I would not give up my swim platform and open stern. Of course the access in my 21 ft BR is better than what you have.

Wonder how many seasons of paying someone to do the annual maint the conversion will pay for?

 

[Lou C]

The one thing I did years ago to my 20' Four Winns was make the rear access better. That helps, but I am still going to install a remote oil filter and extend the block drains with hoses to make it easier to winterize. If I don't have to pull the seats out every time, I can tolerate it.

excuse the dirty deck!

 

[nola mike]

Wonder how many seasons of paying someone to do the annual maint the conversion will pay for?

Yeah, that's what I'm thinking. If you're multiple $10's k into a conversion or buy/sell, just pay somebody...It would take years and years to break even. And although I get it more than anyone how much it hurts to pay someone for something you can do yourself, the time you'll put into the conversion will be WAAAAYYYY more than the time that you need to invest in the I/O's.

 

[Scott06]

Yeah, that's what I'm thinking. If you're multiple $10's k into a conversion or buy/sell, just pay somebody...It would take years and years to break even. And although I get it more than anyone how much it hurts to pay someone for something you can do yourself, the time you'll put into the conversion will be WAAAAYYYY more than the time that you need to invest in the I/O's.

yeah and I think Muc did a synopsis here of why the extended warranty purchase costs for OBs keeps going up... that they are finding they cost more than expected to maintain. If there is one guy on here who knows his chit its muc...

Sunday on the lake we had 5-6 people on the sunpad and swim platform... in and out of the water. on our searay the drive is tucked under the built in swim deck. For us this is perfect

 

[tpenfield]

If I boated on a lake my current boat would be perfect for us as well. For the ocean, it is less than perfect. Not that any boat is actually perfect.