FUBAR Merc 3.0

PBRman

Seaman Apprentice
Joined
Aug 31, 2010
Messages
43
Hello,

I have 1992/3 Merc 3.0 with alpha one outdrive. The engine had been knocking (feeling like it's not in gear) at low speeds and fine at high speed, also fine at low speeds after coming from high speeds. This insinuated worn clutch dog, something I don't have the facility/tools/knowledge to investigate. They dumped the boat in the water and saw that the oil pressure was low. Looking at the oil dipstick it is a silvery milky substance. The mechanic there said this means water in the oil and leak, the oil was changed for the beginning of the summer and fine then (probably used the boat 30ish days this summer with knock slowly getting worse). He said that basically means a new block ($3200ish). It stalls at idle as well. I now have a fun decision and I welcome recommendations or other options: pay for a new block, buy a new boat (this one was circa five grand with one grand put into it immediately.).

Money right now is too tight to get a new and high quality enough boat for waterski optimization (our only use), so the new boat is off the table for now (unless someone wants to buy this one) but I should have a lot more dispensable cash come spring. I really do like the hull and interior and it is in good condition minus the whole engine part. I could also change the oil so the bearings aren't being quite as badly destroyed to get me through to October (supposed to be camping on a waterlocked campsite Thursday Sept 1 though Labor day). A new block won't find its way here in a week supposedly so this seems very feasible if the one I have now is trash anyway.

Is there any reason to get a second opinion? Thoughts, suggestions, hope?

Thank you,
-Sean
 

Silly Seville

Senior Chief Petty Officer
Joined
Dec 5, 2009
Messages
798
Re: FUBAR Merc 3.0

Do you REALLY want to keep driving a boat with a bottom end knock? Changing the oil isn't going to extend your running time. It will just give you a false sense of security for a time, and insure that you have catastrophic engine failure when all of the crank and camshaft bearings ingest metal shavings. I would retire the boat until you can afford to make the appropriate engine repair/replacement. BTW, an engine rebuild is less expensive if you don't have a piston hole through your block. Just my 2 cents...;)
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,234
Re: FUBAR Merc 3.0

used low $ 3.0's are all over. Also, $3200 seams really high for a 3.0. For that price you can buy a Big Block. the last 5.7 long block that I bought was $2200. Michigan Motorz lists the 3.0 for $1700
 

PBRman

Seaman Apprentice
Joined
Aug 31, 2010
Messages
43
Re: FUBAR Merc 3.0

used low $ 3.0's are all over. Also, $3200 seams really high for a 3.0. For that price you can buy a Big Block. the last 5.7 long block that I bought was $2200. Michigan Motorz lists the 3.0 for $1700

For my generation (1992/93) Michigan Motorz has it for $1999 + $150 for the crate + $X shipping. The one I was looking at was 2600 after shipping with the 3200 calculated by adding tax and labor, by having them order it I also don't have to worry about ordering the wrong one. I was thinking about a bigger block as well since I've always wanted a better hole shot, but I'm guessing this engine just hasn't been working properly from day one which gives me hope for a new 3.0. The engine well (correct word?) probably isn't wide enough for a 4.3 and I would also need a new out drive.

As much as I hate to say it, this season is pretty much over :(, (and looking like definitely over for me :mad: because any of these engines will be a few weeks out, making it practically winter here. So I might just wait and see what I can find in newer boat over the course of the winter. If nothing comes along, I'll get this one redone come spring.

Thank you!
 

PBRman

Seaman Apprentice
Joined
Aug 31, 2010
Messages
43
Re: FUBAR Merc 3.0

Do you REALLY want to keep driving a boat with a bottom end knock? Changing the oil isn't going to extend your running time. It will just give you a false sense of security for a time, and insure that you have catastrophic engine failure when all of the crank and camshaft bearings ingest metal shavings. I would retire the boat until you can afford to make the appropriate engine repair/replacement. BTW, an engine rebuild is less expensive if you don't have a piston hole through your block. Just my 2 cents...;)

The damage is already done, so if it was a one time leak (perhaps a bad winterization?) and I clean the oil and replace it with something thick, would there necessarily be metal shavings remaining? I don't really drive slow anyway and it's not having issues on plane. I don't see why, for any reason other than Murphy's law, catastrophe would happen right after an oil change?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,234
Re: FUBAR Merc 3.0

If money is really tight, rebuild your existing motor

RPM machine has 3.0 master kits for under $500 After machine shop work at a local shop, and you doing the labor yourself your into it for about $1200-$1500.
 

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
Re: FUBAR Merc 3.0

RPM machine has 3.0 master kits for under $500

Sounds about right. The machine work on my engine cost less than $500, turn crank, bore engine, deck block, rebuild head etc. The only thing they didn't do was resize the rods as they checked OK.
 

Ryan50

Petty Officer 2nd Class
Joined
Feb 17, 2010
Messages
109
Re: FUBAR Merc 3.0

Keep looking for a used 3.0 or rotten boat with a 3.0 and swap it. I bought a rotten sunbird with a good running 3.0 and swapped it. Did it for 600 bucks.
 
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