Advise: Potential Purchase of a 1989 Mercruiser Alpha One

[Demolitron]

Hello,

I'm looking at a boat powered with a 1989 Mercruiser 3.7L Alpha One Powertrim XD. It is a 1989 Wellcraft 180 classic hull. The owner says he can see the serial # plate but can not read it. I am going to look at it on Saturday to see for myself.

He says that the boat hasn't been on the lake in 10 years. It was not fogged before storage, but has been covered indoors for that time. The fuel tank was not empty when stored.

I was going to go there with a tool set, a battery, and some testers to evaluate the engine.

First I would remove the plugs and fuel line. Then spray in some penetrating oil, like MMO, and try and turn it over using a breaker bar on the crank pulley to see if it was seized. Then try the starter using my fresh battery and go for a compression test. I assume the impeller is trash so if I don't hook up to the hose could I do more damage?

Also, are they telltale signs that the manifolds/risers are corroded/shot? Can I tap on them and listen for a particular sound, or look for the presence of corrosion at the mating surfaces?

I assume that I'll need to replace all the transom rubber after all this time has gone by. I also assume, because of the fuel varnishing after 10 years, that I'll need to rebuild/clean the carburetor, replace the fuel tank, filter, water/fuel separator, and lines. (Or is there a way to clean these out?) Would it also be likely that I'll need to replace the fuel pump, or can I rebuild it with a kit?

Regarding the engine coupler, if the motor did settle/shift could it deform the engine coupler after all this time. I've read that the engine alignment should be done every time the drive if off. Which seems that would normally happen every one to two years. Could the rubber in the coupler degrade after all this time and need replacing?

I am trying to be pessimistic about this so I don't get too surprised if I buy this boat and need to replace and repair a lot before I can get it on the lake. I am mechanically inclined having rebuild import auto engines before, and I have replaced the gears/bearings in and resealed the lower unit on my outboard.

Thanks for your time.

 

[Demolitron]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

I should also add that he said the block drains had been removed. I live in Las Vegas so freezing temps in a garage are not encountered too often. I will of course check anywhere I can for a cracked black.

Thanks.

 

[Bondo]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

1989 Mercruiser 3.7L

Ayuh,....... It's the Infamous Mercruiser 470,.... Merc's Better Idea that Wasn't......

Keep Looking,... Get Away for that Deal.......

You're setting yourself up for a Heartache,.....

It's a Buyer's market out there,.....
Everybody Thinks they're Broke,+ They're selling their Toys........

 

[Demolitron]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

Thanks for that information.

I always want to find out more about these things. From my ongoing research the Merc 470 had a custom aluminum merc block and used a cast iron head from a Ford 408? Then the different expansion rates of the metals causes head gasket failures. Also, the circulating pump being located on the front of the cam creates a failure situation in the seals there.

What else goes wrong with these engines?

Thanks!

 

[bomar76]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

Curiousity killed the cat...

lets see, some more issues w/ the 470:

Outboard style charging system that was weak, trouble prone and outrageously expensive to fix....
a method of adjusting valve lash that involves swapping out different lenght pushrods...
heads that are almost impossible to install correctly unless you are a 470 trained tech...
Early models had an undersized heat exchanger....

should we go on?

 

[Demolitron]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

I'm busy reading the archives here on iBoats, although I haven't yet heard about the difficulty installing the heads, I'll have to look that up. Thank you for the info.

Given this engine's infamy, I don't think I'll be running it around my lake. I'm somewhat insane, so I'll start researching an engine swap, all depends on what the seller will do regarding price.

 

[Bondo]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

so I'll start researching an engine swap,

Ayuh,......

Why not just find a Different boat to Buy,..??..??

 

[TilliamWe]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

I'm somewhat insane, so I'll start researching an engine swap, all depends on what the seller will do regarding price.

That price needs to be "free" to make it worth changing the engine! You'll need at least an I6 in there to replace the power of that 3.7. A V-8 would be better, though. So those aren't cheap. Then there is the need for All the stuff forward of the transom plate. Oh, and the need to make front motor mounts, cause the front mount for the 3.7 won't work for anything you put in there. And the outdrive ratio should be changed if you put in a 5.7 cause you'll end up needing a 27 pitch prop or something weird. The list goes on.

I'm with Bond-o. Why not buy another boat that already has a good engine in it?

 

[bomar76]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

Yeah the whole idea of buying that relic and investing a sh!tload of time, effort, and moola into making it something else is a head scratcher....

 

[Big Boat Bay Buster]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

My advice is to NOT touch the engine. After sitting for 10 years I would assume that everything is toast and needs replacement. If you like the boat, make an offer based on engine replacement. Lets say you spent the whole day bringing that engine back to life and it seems like a good engine, then the guy is going to set his asking price accordingly. Then if you don't pay, he will then advertise it as "Good Running". I had a boat with a 470 and loved it! One reason I loved it is because the previous owner did ALL the work to get it running good. I just enjoyed the power and economy and made sure it did not overheat. Unless its a mint 470, walk the other way!!
Chris

 

[ziggy]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

Unless its a mint 470, walk the other way!!

even if it is mint, walk the other way...

Why not just find a Different boat to Buy,..??..??

this sure seems like a great idea. why waste yer time when it's a buyers market right now. and even if it wasn't a buyer's market..... there's gotta be something out there that's better than an engine with many known design flaws.... set yer self up some criteria as for what ya want, or don't want in this case.... 470's and omc's were on my don't even bother looking at list when i was buying a year or so ago, no matter how cool the boat was...

 

[rodbolt]

Re: Advise: Potential Purchase of a 1989 Mercruiser Alpha One

I agree with the rest and I was actually trained with the 3.7, the open deck block designwas also a drawback, why would someone pull the block drains on a freshwater cooled,50/50 A/F mix, in the block?
doesnt make sense.
yes a few of those engines actually survive, most did not and parts when avalible can get very expensive.
and yes, its a buyers market, we have a 24 Albermarle on the lot with a 5.7 MPI volvo SX package I installed 2 years ago, has maybe 25 hours on it, boat and trailer are going for an asking price of 14K, no takers in a year.