I/O vs OB

[jake100]

Other than power to weight ratio and ease of replacement why is the O/B favored over I/O on trailered saltwater boat? Jake

[inaforty]

I wouldn't want to deal with exhaust manifolds and risers or the outdrive boots and U joints.

Outboards have there own issues.

Pick your poison.

[spareparts]

Beyond weight and performance issues, repairs and serviceability are major issues. You can take an I/O and basically break it down to three parts, engine, transom plate, and drive. Each one of these can create enough issues to total out a boat. Manifolds and risers are considered a consumable on an I/O, in salt water its advisable to replace them at least every 5 seasons(sooner for the new dryjoint Mercruisers). Salt water stays in the cooling jackets after you run your engine, so its still corroding while you sleep. The drive retails for over $5500 and without the proper tools, isn't owner repairable. Transom plate bellows need to be replaced periodically and it isn't an easy job($$$). If you neglect them, it can sink your boat or at the very least wipe out your gimbal bearing. Also consider on an I/O you are bringing raw water into the boat, any leak doesn't just add water to your bilge, its also corroding parts that shouldn't be wet. Whats just a water leak in fresh water is now a bad alternator, starter, or corroded electrical system, and I've seen stuck throttle bodies from salt spray. The labor issue in repairing an I/O makes a big difference, on an outboard you can do a four bolt tune up if it gets too bad. The newer outboards are getting more and more expensive to repair and the amount of parts involved are getting closer. The newer I/O engine are getting more and more complex as well and i see them pricing themselves out of the market. I can pick and chose components to piece together an I/O and come up with a package that would rival a new four stroke in serviceability, resistance to corrosion, and performance. But no on offers that package from a factory(it would combine elements from several different manufactures), In fresh water, it wouldn't bother me one bit to run an I/O, but in slat, I'll stick to 2 stroke outboards

[Destroyer]

Originally Posted by spareparts

Beyond weight and performance issues, repairs and serviceability are major issues. You can take an I/O and basically break it down to three parts, engine, transom plate, and drive. Each one of these can create enough issues to total out a boat. Manifolds and risers are considered a consumable on an I/O, in salt water its advisable to replace them at least every 5 seasons(sooner for the new dryjoint Mercruisers). Salt water stays in the cooling jackets after you run your engine, so its still corroding while you sleep. The drive retails for over $5500 and without the proper tools, isn't owner repairable. Transom plate bellows need to be replaced periodically and it isn't an easy job($$$). If you neglect them, it can sink your boat or at the very least wipe out your gimbal bearing. Also consider on an I/O you are bringing raw water into the boat, any leak doesn't just add water to your bilge, its also corroding parts that shouldn't be wet. Whats just a water leak in fresh water is now a bad alternator, starter, or corroded electrical system, and I've seen stuck throttle bodies from salt spray. The labor issue in repairing an I/O makes a big difference, on an outboard you can do a four bolt tune up if it gets too bad. The newer outboards are getting more and more expensive to repair and the amount of parts involved are getting closer. The newer I/O engine are getting more and more complex as well and i see them pricing themselves out of the market. I can pick and chose components to piece together an I/O and come up with a package that would rival a new four stroke in serviceability, resistance to corrosion, and performance. But no on offers that package from a factory(it would combine elements from several different manufactures), In fresh water, it wouldn't bother me one bit to run an I/O, but in slat, I'll stick to 2 stroke outboards

And that, Jake100, is why we listen to guys like Spareparts and TheFermanator. They do this stuff for a living, and when they say jump, we only ask how high. The amount of knowledge that was just given to you in his reply would cost you tens of thousands of dollars by actually experiencing first hand the problems with an I/O in salt water.

Oh, FYI, a "four bolt tune-up" refers to the fact that you can change out an outboard engine by simply removing the 4 bolts that hang it on the transom.

[bradford]

Excellent post Spare!

[RidgeRunner]

The convenience of servicability and ease of getting to the engine with the boat on the trailer makes the OB my choice. Space inside the boat is minimized with an I/O as well. Close the transom and add a bracket and now I have 8 more square feet of deck at the transom of my 20' er. Not to mention the outboards are just plain cheaper from the beginning. Money drives the world..
I heard some outrageous numbers for engines and drives out of the Miami boat show. It seemed so high I wouldn't even repeat it, this crowd would think I am trying to be the big shot... LOL! Well maybe some of the new members got the disposable income, but not I..

The trend for go fast fishing vessels is also moving toward big outboards. Seven Marine is now very much a player in that arena. Nor-tec racing boats/pleasure boats had six boats at the Miami show and only the 50 footer had I/O's all other were Outboards. Telling.