I thought that this article by boattest.com is a good overview of the reasons and the various options for repowering gassers:
https://www.boattest.com/view-news/5376_should-you-repower-an-old-sterndrive-boat
I was a little surprised at the comment that at 1,000 gassers are subject to repowering. Heck I hope to get 2,000 hours out of my new outboard gasser while running it pretty hard. Maybe gasser owners run the snot out of theirs or do no maintanance.
Anyway the article discusses the following progression of repowering options, all of which are applicable to diesels depending on model:
Replacing with a short block. A short block is a new block or sometimes totally remachined older block with new parts. It usually consists of the block, crankshaft, con rods, pistons but no head, oil pump or oil pan and definitely no marinization parts like a water cooled exhaust manifold or main heat exchanger.
Replacing with a long block. A short block plus all of the non marinization parts. Not sure if it includes intake system.
Replacing with a complete running take out that has been certified by a major supplier like Mercury. This probably avoids surprises that can come from buying from an individual and should come with some sort of warranty. Expect some wear but should not affect operation.
Replacing with a factory reconditioned engine. In this case essentially only the block is used and even that it totally remachined. All other parts are new.
Replacing with a brand new engine.
The last three seem to be more applicable to diesels as I have not heard much of the others being used. A short block replacement is pretty common for gassers because that includes all of the parts that wear out in 1000 hours
David
https://www.boattest.com/view-news/5376_should-you-repower-an-old-sterndrive-boat
I was a little surprised at the comment that at 1,000 gassers are subject to repowering. Heck I hope to get 2,000 hours out of my new outboard gasser while running it pretty hard. Maybe gasser owners run the snot out of theirs or do no maintanance.
Anyway the article discusses the following progression of repowering options, all of which are applicable to diesels depending on model:
Replacing with a short block. A short block is a new block or sometimes totally remachined older block with new parts. It usually consists of the block, crankshaft, con rods, pistons but no head, oil pump or oil pan and definitely no marinization parts like a water cooled exhaust manifold or main heat exchanger.
Replacing with a long block. A short block plus all of the non marinization parts. Not sure if it includes intake system.
Replacing with a complete running take out that has been certified by a major supplier like Mercury. This probably avoids surprises that can come from buying from an individual and should come with some sort of warranty. Expect some wear but should not affect operation.
Replacing with a factory reconditioned engine. In this case essentially only the block is used and even that it totally remachined. All other parts are new.
Replacing with a brand new engine.
The last three seem to be more applicable to diesels as I have not heard much of the others being used. A short block replacement is pretty common for gassers because that includes all of the parts that wear out in 1000 hours
David
