I/O (Sterndrive) Conversion to Outboards

[tpenfield]

Well, I know that I have aged . . . I can no longer contort my body to reach under the engines to check the water intake hose clamps. As I was trying to do so over the past few days, I said to myself . . . . "well that just perfect"

I used to not mind maintaining the I/O engines, but it is starting to wear on me. I was also thinking . . . 'it's good that the gimbal bearings and U-joints are perma-lube type, because now I don't have to remove the outdrive each year' . . .

Anyway . . . I plan on working on the bracket (or hull extension) at the end of this season, then see about having a re-power shop take care of the OB's.

 

[Lou C]

I’m very been at that same point for the past few years I might be a bit older than you Ted lol! I have permanently lubed ujoints & front wheel bearings in my 98 Jeep it’s 27 years old with 182,000 miles & I have not had to change one yet!
With the drive, I’d be worried about the bellows possibly leaking and also the fact that when I pull the drive there is always plenty of grease in the ujoints & gimble bearing but on the driveshaft splines, not much. OMC & Volvo never had the grease fitting in the coupler so you could grease it. Although my brothers 2020 Chap with the Merc 4.5 had that but there was no way to reach it!
Freshwater guys might be able to pull it every other year but us salt water guys…well not so much….and yes I see an outboard boat in my future for sure. Less and less I/Os in my harbor this day…

 

[tpenfield]

I’m very been at that same point for the past few years I might be a bit older than you Ted lol!

I'm 69 ish . . .

 

[Lou C]

lol same
As old as…the small block Chevrolet

 

[redneck joe]

I'm new to the 59ish range, but last couple three years my body is shot. I currently need 8 different ortho surgeries, hence why I'm in an 2000 lb set up not a 7800 cruiser on a trailer. And Def no crawling around a bilge wrenching on an engine. An eye level smoker is way easier to drink beer whilst working.

 

[tpenfield]

Summer Update . . .

I've been doing a little bit of research on the outboard engines. Planning on having Mercury, Yamaha, and Suzuki quoted.

Key Spec's/Features

300-350 HP Twins
Mercury is more of a known commodity . . . planing on the same feature set I have now with the I/O's (DTS, Smartcrap, Joystick)

Suzuki has a dual prop version, but they are a bit on the heavy side. I think they rely on third party add-on for joystick docking (Optimus?)

Yamaha recently came out with 'Helm Master EX', which is their version of joystick docking . . . Previously, the joystick options were done via Dometic/Optimus. The Yammy 300 HP (V6) are well regarded. The 350's have a blemished history, I beleive.

If I go with 300 HP, I may tweak the hull extension accordingly to get better planing ability.

BTW - I noticed a set of static trim tabs on the Cruisers Yacht 338 OB versions. Not sure all of the boats had them, but it tends to indicate not enough hull for the boat, as I have always thought.

 

[thedinz]

lol same
As old as…the small block Chevrolet

I wouldnt let go of that boat if i were you but i understand, let me know when its for sale

 

[Scott Danforth]

Ted, don't think tabs .....think K-planes. 3 actuators and 5 square ft of surface

 

[tpenfield]

Ted, don't think tabs .....think K-planes. 3 actuators and 5 square ft of surface

I’ve started using a bit more trim tab to get more stern lift. It makes a big difference.

 

[tpenfield]

I was wondering about the choice of engines . . .

I expect that mercury will be the most $$$ and they are going to be V8 (4.6L) or V10 (5.7L), depending on power choice. Suzuki seems to own the re-power market . . . not sure if that is based on price or other factors.

The Yamaha and Suzuki are using V6 configurations in the 4.0-4.4L range to get 300-350 HP. I would expect the Mercurys to have more low-end torque. I'm wondering which ones are more fuel efficient? In the I/O world the smaller engine (same boat) tended to use almost as much fuel, if not more, because it needed to run at much higher RPM to get the needed power. Not sure if that holds true with outboards.

Anyway, I hope to have some pricing of the 3 to compare in the next month or so.

 

[Pmt133]

I'll preface this by saying I am very far removed from the current outboard market in terms of ownership... but I did go down the rabbit hole looking into the current crop of them. My understanding is that merc really did their homework on these new ones and spent a ton of time tuning them to be really efficient. The yamahas are the lightest, the merc in the middle and the Suzuki heaviest. Granted there is only a 75 pound spread between them but still.

The few people I know with the V8s say they tested their hull with the others and the mercs were hands down faster everywhere as well as more efficient... though splitting hairs on that. (.1 to .2 mpg but at higher speeds for the same economy)

Thats all I got.

 

[alldodge]

Merc used superchargers for a short time with smaller blocks and found out there were not reliable.

 

[Lou C]

Apparently Merc also tried to make their mid size Obs easy to service as well...
Suzuki has one big advantage for single engine boats, a DP set up, don't think anyone else has that on an OB.

 

[Pmt133]

Merc has dual props on the 600hp outboard I think. Obviously not on the smaller units.

 

[dingbat]

Suzuki’s popularity in the re-power market is pricing.

Unless Toyota comes out with an outboard between now and then, I’m going Honda on my next re-power

 

[tpenfield]

one of my big ‘wants’ in a re-power is to have joystick docking. That puts Mercury at an advantage, because they have an integrated system that has been around for a while.

I have not seen much in the re-power space and digital controls from Honda; not sure if they focus there.

 

[tpenfield]

Looks like Honda has a 350 hp, no 300 hp. The weight is about 100-150 lbs more that the other single prop OB’s

 

[Scott Danforth]

Ted, you know the prices of used 338 outboards are coming down. it may be less money to simply sell what you have and buy what you want. there is a 2019 for $249k and a 2022 for $279k (with new custom interior)

 

[tpenfield]

Ted, you know the prices of used 338 outboards are coming down. it may be less money to simply sell what you have and buy what you want. there is a 2019 for $249k and a 2022 for $279k (with new custom interior)

Yes, I have been checking. . .

Of course my boat is also coming down in value, so the 'upgrade price' is still significant.

Other factors are . . .
> I'm not in love with how CY did the outboard versions. They took away about 15" of swim platform space with a notch, rather than a mere extension. My quick math indicated that this was probably done to maintain the balance point (CoG) of the original hull.

> I have noticed additional planing tabs on the outboard version, which I take to mean that the boat does not plane well-enough for its weight. The I/O versions don't either.

> To make a change over the course of the winter, I would probably have to sell my boat for about $110-125K (BUC value estimate is $150K, NADA is $120K). Boat market in the Northeast is down significantly from the Covid years.

> Then I have to figure the usual fix-its and adding the solar charging and other stuff I've done to my boat.

> Most of the OB versions for sale are in Florida (or long distance), which is more complicated buying long distance. If something came up in the Northeast, it would be worth a look.

 

[redneck joe]

But if you buy outboards we won't have the continuation of this thread. I can see it easily reaching 100 pages on a refit....