Outboards rebuilds and diesels

[unbusted67]

I’m wondering what the state of the industry is in regards to outboards and rebuildability. Are people getting anywhere near the lifespan out of outboards that you can out of a diesel?

I’ve currently got close to 8,000 hours on a Cummins qsb 6.3. My understanding is that the average lifespan of an outboard is about 2500 hours.

I’d recently heard that some builders are making sleeved outboard blocks for easier rebuilding? Anyone know anything? I’m coming from the world of inboard diesels and know very little about outboards.

[thomm225]

My outboard is 10 years old bought new in 2011 for $1550.

If it fails, I'll just buy another. Why would I want to rebuild when I can replace for such a low price especially as compared to the price of a diesel.

It doesn't use much oil. I think I have added a few ounces since February so it appears it's fine for another 5 years or more. It's a four stroke, 5 hp pushing a 6600 lb displacement boat and I have changed the plug one time.

https://www.youtube.com/watch?v=ri0c5GnZ1I8

https://www.youtube.com/watch?v=uNl2tPRC-Tw

[tkeithlu]

Reliability has gone way up with the switch to four strokes, but I doubt we'll ever get from a gasoline engine what we get from a diesel. Simply having a third system (electricity) that can fail reduces reliability.

Then again, they cost less. If you want to maximize life in an outboard, don't do any hard accelerations, don't run at maximum RPM, and change the oil frequently.

[Adelie]

If you can get 1/3 the lifespan out of an outboard for 1/5 the price you are definitely money ahead on purchase.

Access for maintenance is much better.

Fuel economy is about 60% that of a diesel inboard so in the long run you lose in the money dept.

If the outboard is stern mounted you will probably not be able to run is when winds above 15kt or so are generating wave.

If the motor is mounted in a well like AtomVoyages then the motor will be usable in higher winds.

[vpbarkley]

Inboards offer a longer life span, high current charging, hot water, higher thrust and fuel economy.

Outboards offer low cost and completely modularity - removal for servicing or repowering takes minutes.

[Grattaway]

Depends a lot on how you use and maintain them
I have recently replaced a pair of 70 hp Yamaha 2 stroke outboards with younger versions. Both had done more than 6000 hours which is a lot but boat originally belonged to a friend of mine and he was a fishing guide - freshwater lakes. However lots of fish farm and small operators do use outboards - now mostly 4 stroke - and run hours in the thousands is not uncommon if well maintained

[kapnd]

I’ve found that an inboard is much less likely to be stolen off the boat!
Many of the anchorages I’ve visited are inhabited by “opportunists” who prey on unwary visitors.

[thomm225]

Originally Posted by kapnd

I’ve found that an inboard is much less likely to be stolen off the boat!
Many of the anchorages I’ve visited are inhabited by “opportunists” who prey on unwary visitors.

Good thing small outboards can be removed and stored. Mine weighs 57 lbs and pushes the boat as well as the 352 lb Bukh 10 did but without the smell or leaks into the boat

[unbusted67]

[QUOTE=thomm225;3522382]My outboard is 10 years old bought new in 2011 for $1550.

If it fails, I'll just buy another. Why would I want to rebuild when I can replace for such a low price especially as compared to the price of a diesel.

It doesn't use much oil. I think I have added a few ounces since February so it appears it's fine for another 5 years or more. It's a four stroke, 5 hp pushing a 6600 lb displacement boat and I have changed the plug one time.

Sorry, I should have been more clear. I am specifically talking about higher HP engines. A new 350 hp outboard is actually more expensive than a similar horsepower diesel. The power curves on outboards seem to be what you are actually paying for. They are, in essence, built to get you up on a plane and keep you there. Inboard diesels take a lot more HP and weight to accomplish the same task. I guess I am just curious if the outboard industry is doing anything to improve longevity in industrial applications. I am not interested in outboard usage in sailboats.