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Trouble on the water

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wes910

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I have a 01 mercuiser 5.0. I put a new prop on it and took it for a trip today. We ran around for about 45min and stopped 2 times to change tubers out. On the 3rd stop when i turned the key off to the motor kept running for about 20 seconds it sounded very rough then died i noticed a bit of smoke or misty came out of the spark arestor. I Looked at it for a few minutes and tried to restart it. it sounded like a bad battery starter spinning slow , straining to turn the motor over but would never start. I also noticed that the gauge lights where not working the depth sounded was not working and the beeper wasnt beeping with the key in the on. any ideas where to start?
 
When you shut off the engine you didn't allow the engine to idle a few minutes or even a minute.

It's called dieseling or run on, you should have quick turned the key to run again when that happened.

The engine could have been running backwards and you pulled water into the cylinders.

What this means to you, pull out the spark plugs reset the main breaker " the big red button near the starter " crank the engine see if water shoots out the spark plug holes.

Post back.
 
Last edited:
Master mechanic said:
It's called dieseling or run on, you should have quick turned the key to run again when that happened.

The engine could have been running backwards and you pulled water into the cylinders.
Click to expand...
Agreed.

Some may suggest ignition timing..... but your ignition spark source has been eliminated when you shut down.

What usually causes this... is high cylinder temperatures, a lean low speed F/A mixture, piston deck carbon deposits, and a high idle RPM.
Allowing the engine to cool down will help.

Ultimately, you'll want to fatten up your low speed mixture (if it's too lean now), and lower your idle RPM to within specs.



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Master mechanic said:
When you shut off the engine you didn't allow the engine to idle a few minutes or even a minute.

It's called dieseling or run on, you should have quick turned the key to run again when that happened.

The engine could have been running backwards and you pulled water into the cylinders.

What this means to you, pull out the spark plugs reset the main breaker " the big red button near the starter " crank the engine see if water shoots out the spark plug holes.

Post back.
Click to expand...

I pulled they plugs and they where wet with water....Should I spin it over a few times reinstall the plugs and try to start it?...or do I have more problems now?
 
wes910 said:
I pulled they plugs and they where wet with water....Should I spin it over a few times reinstall the plugs and try to start it?...or do I have more problems now?
Click to expand...

Yes

pull ALL spark plugs, some are not easy to do so you may need a open end wrench and/or a thin wall socket. (5/8") Be careful they break easy.

After all plugs are pulled, pull the coil wire out of the DISTRIBUTOR end and place the end on or near a part of the engine that is metal. Maybe use some paint blue masking tape or duct tape to hold it. DO NOT PUT NEAR A GAS SOURCE...

Now crank the engine over several times and see what comes out. If there is any quantity of water it will shoot out in a powerful stream. DO NOT LOOK AT SPARK PLUG HOLES WHILE CRANKING IT OVER.



do this a couple times then reinstall the plugs making sure you have the correct wire on the correct plug and see if it will start.

Also before doing anything check the oil dip stick, see where the oil level is. If it is over filled that may be water sitting on the bottom of the oil pan from sitting for a while since last used (IF water got past the rings of the pistons) Also check after cranking and see if it becomes milky.
 
I put everything togther and it fired right off. I let it idle for about 15mins in the drive and the oil it clean. How common is somthen like this? This is my first stern drive(I came from outboads). Im guessing the starter doesnt have enought power to bend the the valves?
 
I have seen connecting rods twisted.

You should be ok.

If it happens again your aware now quick turn the key to run.

You got good advice from other members also.
 
Gets some Mercury PowerTune and run it thru the engine per directions to clean out any carbon buildup.
 
You want to flush the engine?

Drain one quart of oil add one quart automatic trans fluid run the engine a half hour drain oil new filter your done.
 
Flushing or no flushing, you'll want to get this engine up and running soon, so that the moisture can become vaporized and boiled off.... in particular from behind the piston rings.

I'm not discounting a good oil system flushing....... I'd do both.


Keep us informed! :D

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