1993 3.0 mercruiser stall and engine sieze

cootyman

Recruit
Joined
Nov 7, 2019
Messages
1
Boaters, this is a head-scratcher. I've had this 1993 Bayliner for a long time. Very low hours. Used once or twice a year, then about the third time out this year, we are running down the lake and ol'blue just went dead for no apparent reason. Oil pressure good, battery good, starter good, all connections good. Running perfectly. Not smoking, clean oil, No miss whatsoever. Had to be towed in, and the engine was siezed. I removed the spark plugs, sprayed with PB Blaster, then bumped the starter to loosen the engine. After re-installing the plugs, she fired right up. Ran it all day with no problems, then two weeks later same sieze! Any advice from all you mercruisers out there would be very much appreciated.
 

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
I had the same problem, it was cause by: 1- bad ignition switch killing the ignition. 2- Burned out exhaust shutters not stopping the exhaust being flooded.

I would check the ignition switch and safety lanyard (deadmans switch) wiring, to make sure the wiring is good and connections tight. (Mine was a defective key switch) Also, check the engine wiring harness canon plug.

Replace the exhaust shutters, since they are supposed to keep the engine from hydro-locking when the exhaust gets swamped (sudden stop).
 

Lou C

Admiral
Joined
Nov 10, 2002
Messages
6,802
When you say seized do you mean it would not turn over with the key? Did you try pulling the plugs to make sure it was not hydro locked? Sounds like you did any water come out and how did the plugs look? Also make sure the drive oil is not low; the drive could be binding up and locking up and stalling the engine.
 

achris

Moderator
Staff member
Joined
May 19, 2004
Messages
24,848
Sounds like a complete loss of electrical power to the engine ignition system. Does not sound like a seize. I would put a test lamp on the coil positive and when/if it happens again, check the light. If it's off, or dim, that's your culprit. Start chasing down an electrical fault.

Several places to start right off the bat. Check the pins in the big canon connector (the one that plugs in the instrument harness), and the common one, look for corrosion on the ends of the 20A fuse in the instrument cluster. If you see corrosion on that fuse, let us know and we can tell you haw to fix it properly (cleaning the corrosion off is a short term fix).

Chris.........
 

jimbo_jwc

Ship Happens
Joined
Dec 19, 2010
Messages
633
I had a similar thing happen to my boat , after testing a lot of things only to free up and run like nothing was wrong .!989 3.0 liter with Alpha One . Here is a simple way to check as it was the top taper roller bearing that finally came apart and jammed the bevel gears .Take the top off and inspect as I dropped the lower unit and didn't free up until I pulled the whole drive .
 

achris

Moderator
Staff member
Joined
May 19, 2004
Messages
24,848
I had a similar thing happen to my boat , after testing a lot of things only to free up and run like nothing was wrong .!989 3.0 liter with Alpha One . Here is a simple way to check as it was the top taper roller bearing that finally came apart and jammed the bevel gears .Take the top off and inspect as I dropped the lower unit and didn't free up until I pulled the whole drive .

If it was damaged gears, it wouldn't have restarted and been fine for a while before happening again.

This sounds more like an electrical problem than mechanical. Mechanical problem don't 'solve themselves' for a short time and then happen again.

Chris........
 

tank1949

Ensign
Joined
Apr 4, 2013
Messages
951
If seized perhaps hydo lock or jammed connecting rod internally. Usually hydo-lock can't be cleared unless remove water from piston/cylinder. Perhaps you are describing something different?
 

Scott Danforth

Grumpy old guy who plays with boats
Joined
Jul 23, 2011
Messages
33,384
most likely hydro-locked

fix your flappers, then find out why the boat motor died.
 
Top