What is it like owning a 20yr old merc cruiser on a trailer boat?

SpearTub

Petty Officer 2nd Class
Joined
Jan 26, 2021
Messages
109
Am I nuts. I know how to service a 140hp outboard but no idea about a merc cruiser. I guess the one plus side the leg is out of the water when not in use.

Its a Merc Cruiser 3.0lx and leg. I presume thats a non turbo? Are these engines hard to work with? The hood provides easy access, Im just new to them so not sure if my outboard knowledge can transfer over.

The price of petrol is $2.50 here and diesel $1.70. Thats a big incentive. But not if he engine will cost $5k to repair haha.

Any tips on what to look for?
 
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achris

More fish than mountain goat
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May 19, 2004
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27,468
The 3 Litre engine is petrol, not diesel.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Am I nuts. I know how to service a 140hp outboard but no idea about a merc cruiser. I guess the one plus side the leg is out of the water when not in use.

Its a Merc Cruiser 3.0lx and leg. I presume thats a non turbo? Are these engines hard to work with? The hood provides easy access, Im just new to them so not sure if my outboard knowledge can transfer over.

The price of petrol is $2.50 here and diesel $1.70. Thats a big incentive. But not if he engine will cost $5k to repair haha.

Any tips on what to look for?
the 3.0 is an archaic lump of iron with its original design dating back to 1960.
its a bored and stroked version of the old Chevrolet 153 cubic inch 4 cylinder which shared the bore and stroke of the 230 cubic inch 6-cylinder

its a forklift motor adapted to marine use.

both engines operated on the same otto cycle
both engines require maintenance

however I/O's require proper winterization
 

Scott06

Admiral
Joined
Apr 20, 2014
Messages
6,777
Am I nuts. I know how to service a 140hp outboard but no idea about a merc cruiser. I guess the one plus side the leg is out of the water when not in use.

Its a Merc Cruiser 3.0lx and leg. I presume thats a non turbo? Are these engines hard to work with? The hood provides easy access, Im just new to them so not sure if my outboard knowledge can transfer over.

The price of petrol is $2.50 here and diesel $1.70. Thats a big incentive. But not if he engine will cost $5k to repair haha.

Any tips on what to look for?
merc 3.0 is one of the best entry level powerplants out there. What it is is durable, easy to work on, and inexpensive to operate and maintain, what it is not is fast or powerful. If reasonably well cared for will outlast the rest of the boat.

Get a factory service manual for the engine and the drive. You do need to winterize by draining the block. Yearly I would drain the block, change the engine oil, change the drive lube, grease the gimbal bearing and u joints, treat fuel with stabilizer. Most recommend removing the drive annually which doesn't take long (I did skip some years...)

Beyond annual maint-one carb cleaning and rebuild, two water pump impellers, one gimbal bearing, one bellows, pair of u joints, and one input shaft seal was all I did in 20 years of ownership (was 5 years old when I got it).
 

SpearTub

Petty Officer 2nd Class
Joined
Jan 26, 2021
Messages
109
Ayuh,...... Donno,..... Never had one that New,......
hehe you got me, you got me.
what I meant to post was, Ive never owned a petrol inboard. a bit wary, I dont know, I guess something in my head says greater fire risk than outboard, or wrong?
Thanks all. Well sounds like the smart thing to do would be to get a marine mechanic to assess the engine for me prior to purchase. Or offer them half the price and do a new pod conversion on the back haha.
The boats themselves actually look quite nice, similar in some ways to bayliner trophys.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
hehe you got me, you got me.
what I meant to post was, Ive never owned a petrol inboard. a bit wary, I dont know, I guess something in my head says greater fire risk than outboard, or wrong?
Mercruiser haven't had an engine attributed fire for a VERY long time. Most boat fires are caused by owner ignorance (of fire prevention systems on the engine, like NOT automotive carbs, alternators and starter motors) or lack of maintenance. I've owned quite a few boats (as well as having owned my own marine dealership) and the only engine fires I've seen was with an outboard, and a fueling accident (which can happen to outboards just as easily as inboards.
Thanks all. Well sounds like the smart thing to do would be to get a marine mechanic to assess the engine for me prior to purchase.
THAT is a very sound idea.
Or offer them half the price and do a new pod conversion on the back haha.
I've seen many many pod conversions. Not one of them was as satisfactory as with the original stern drive. It's an expensive option, that just doesn't work.
The boats themselves actually look quite nice, similar in some ways to bayliner trophys.
I hope that's in looks only. Bayliner (aka, bilgeliner) aren't great boats.

A stern drive engine is just like a car engine, with a few variations to 'marinise' them. All the tools you have to maintain your cars are the same tools to maintain your stern drive engine. Just learn about the subtleties and ask here before doing anything (too many people start a job, get halfway through then come asking for advice. Only to find out they did (or didn't) do something they should have right at the start and now the job it 10 time harder)....

Chris..........
 
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SpearTub

Petty Officer 2nd Class
Joined
Jan 26, 2021
Messages
109
A stern drive engine is just like a car engine, with a few variations to 'marinise' them.

Chris..........
Yes Ive seen Toyota turbo diesel engines added to boats.

Would it be not worth the money to convert it to a diesel engine?
Yes I meant they just look like Trophys a bit, which imo are the only Bayliner I like, just my 2c.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Yanmar used the Toyota 1HZ engine and got 315hp from it, but since Toyota don't make that engine anymore, it's no longer available from Yanmar. If you really wanted to replace the petrol with a diesel you could, but it would have to be a labour of love. Flywheel housings, exhaust systems and water-cooled manifolds aren't 'off the shelf'. Everything would have to be custom made, and the price goes through the roof.
 
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