Swap out mercruiser 140 to omc sea drive

[madman2021]

I have dumped hundreds of dollars every few months into my mercruiser 140 and I'm fed up with mercruiser products. Had $800 worth of work done to motor and outdrive last week and the last time I took it out the motor started devolping a rod knock and the main boot and outdrive seal busted. There's a v4 omc seadrive in running condition on Craigslist near me that I'd like to know how to swap to my boat and figure out how much more the stern will sit in the water from moving the weight that far back. My boat is a 1986 glasstream 172 cutlass.

 

[matt167]

Re: Swap out mercruiser 140 to omc sea drive

B:reak
Ou
A:nother
T:housand

The Seadrive was an OMC branded engine, and I'm not sure there was much if at all in common with Johnson/ Evinrude, parts are going to be fairly hard to find. They also have that weird bracket. You could buy/ build an outboard bracket that fits in the keyhole, but you would still have to convert the Seadrive to a standard outboard mount.. In reality, just repair the 140. You will have less into it, and it's going to be more reliable. Parts for that 140hp are available over the counter. It's a GM/ Chevrolet 181 CI 4cyl. Lots of rotted boats to get a donor engine from cheap too.

 

[JimS123]

Re: Swap out mercruiser 140 to omc sea drive

IMHO, your boat is too small for a SeaDrive. Too much weight too far aft on a boat thats too short.

In any event, if you go that route better plan on rebuilding the transom since its likely not going to be strong enough for the new mount. You'll have to fill in the hole anyway.

Your GM 181 is one of tyhe most reliable engines ever made. Certainly better than the OMC outboard.

 

[madman2021]

Re: Swap out mercruiser 140 to omc sea drive

The omc seadrive is a standard Johnson/ evinrude v4 cross flow motor. Parts are easily available. My local boat shop carries everything for the seadrive.

The reason I want this is for $600 I can buy the motor and not deal with these ****ty mercruisers anymore. Everything on my mercruiser is new and I meticulously maintain it. Rebuilt the motor and outdrive 4 years ago. Less than 100 hours on rebuild. Replaced head gasket 2wice, all new ignition components, all new wiring, all new exhaust components, new reman carb, all new hoses, the outdrive had full rebuild done 4 years ago. Had 3 upper units go out, one lower unit, all new bellows every few months cause they always leak, new gimbal bearing just about every 2 months, replaced ujoints multiple times, replaced engine coupler once, new control cables every year, 2 trim pumps, oil change every 15 hours, replaced one ram.

Basically I've replaced every component on this boat at least 2wice. It's been the most unreliable motor I've ever owned. Going back to something I know thats reliable. A good ole Johnson/evinrude.

 

[JimS123]

Re: Swap out mercruiser 140 to omc sea drive

The omc seadrive is a standard Johnson/ evinrude v4 cross flow motor. Parts are easily available. My local boat shop carries everything for the seadrive.

The reason I want this is for $600 I can buy the motor and not deal with these ****ty mercruisers anymore. Everything on my mercruiser is new and I meticulously maintain it. Rebuilt the motor and outdrive 4 years ago. Less than 100 hours on rebuild. Replaced head gasket 2wice, all new ignition components, all new wiring, all new exhaust components, new reman carb, all new hoses, the outdrive had full rebuild done 4 years ago. Had 3 upper units go out, one lower unit, all new bellows every few months cause they always leak, new gimbal bearing just about every 2 months, replaced ujoints multiple times, replaced engine coupler once, new control cables every year, 2 trim pumps, oil change every 15 hours, replaced one ram.

Basically I've replaced every component on this boat at least 2wice. It's been the most unreliable motor I've ever owned. Going back to something I know thats reliable. A good ole Johnson/evinrude.

I agree with you completely about the Johnnyrude reliability. Can't beat them. But, as I said before, the Merc / GM 4-banger is probably the most reliable engine out there. It's been in the market since the early 1960's and I would guess that more of them have been sold than any other model.

Your list of repairs tells the story. For example, bellows every few months because they leak??? OMG, did your mechanic know they need to be installed with adhesive?

You need a new mechanic. Sounds like he is your problem.

 

[86 century]

Re: Swap out mercruiser 140 to omc sea drive

I couldn't disagree more about the 140 I have ran those things to he'll and back with next to no problems.
get you a better service guy or figure out what you are doing wrong to break the darn thing.

The one I ran 2010/2011 had no oil pressure at an idle the entire time I owned it.
The same eng was run all summer 2012(sold it to a friend that had been in it and knew of the problem.

 

[Solittle]

Re: Swap out mercruiser 140 to omc sea drive

Parts are readily available for the powerheads for the SeaDrive but not so for the SeaDrive assembly itself. I have two and have had no problems with the SeaDrive. Installation is critical as you cannot change the height of the engine once installed.