I/O conversion

[Kate]

Anyone ever do or have knowledge about an I/O to outboard conversion?

I'm toying with the idea.

[capn272]

Rebuild transom. Get bracket. Hang outboard. Rig outboard. Boat.

Have fun with the glass work, I suppose?

What model boat are you looking at doing it on?

Edit to add - I've seen some IO conversion brackets that use the motor mounts and the existing transom hole.. that might make things a little better?

[billk2632]

Depends on the boat I guess -- but in my opinion they always look like an I/O > Outboard conversion. With very few exceptions, if you want an outboard boat, better to buy an outboard boat - the cost to do it right with a new outboard motor far exceeds the cost of an I/O repower. I guess I always picture and old SeaRay bowrider with an old 2 stroke merc with no decals hanging off the back with a ghetto install job -- the Miami Boat ramps special.

[Kate]

"What model boat are you looking at doing it on?"

24', '86 Condesa with a 350 Merc that runs fine and that I've owned for years. Want more power, especially cruise speed. Looking at new, twin 250's, probably Merc or Yamaha.

If transom needs strength, then marine plywood with glass or stainless steel plate.

I've been doing a systematic restomod on her for years. This definitely will not be a "Miami Boat ramps special."

"[T]he cost to do it right with a new outboard motor far exceeds the cost of an I/O repower."

True. But I don't need a repower. I need a massive increase in power. Best I can tell from the mechanics, I can't get that increase with any of the inboard options.

[billk2632]

Sounds like you have a solid reason for wanting to do this. So many people have a boat with a tired worn out I/O and think hanging a used outboard off the back is a cheap re-power solution -- it's not.

1. I think done right it might look ok, even good on that style boat - traditional flat transom, not trying to hang outboards off a molded in swimdeck or something. Picture a Bertram Moppie that has been repowered with outboards. The did this on Ship Shape TV some years ago.
2. Would think the transom would need a good bit of work to fill in the outdrive holes and strengthen it to hold the two outboards.
3. Assume you would have to install / build brackets.
4. I would do some investigation as to the weight - the two outboards are going to be heavier than the single I/O AND they will be farther aft.

Never done anything like this, so I can only offer my thoughts.
Don't take the Miami Boat ramps comment personally, that's just what comes to mind when I hear about these things.

[Kate]

"Assume you would have to install / build brackets."

Install. There are quality manufacturers of outboard brackets for this type of conversion.

Patching the transom is relatively easy. Beefing up the transom, not so much.

"I would do some investigation as to the weight . . ."

Fortunately, we don't have to invent the wheel. Such conversions have been done right for a while, so there are good calculations and formulas.

"Don't take the Miami Boat ramps comment personally . . ."

I didn't. I thought it was funny. Redneck engineering is often ingenious, even if cringeworthy.