PLEASE HELP!! Mercruiser DIES!!

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: PLEASE HELP!! Mercruiser DIES!!

The intermittent nature of the symptoms you describe are not typically associated with a carb problem.

In my post when I said the negatve side of the coli is grounded and ungrounded I meant that the ignition control unit performs that, and that is how spark is generated. I did not mean for you to try to ground the coil on purpose. I wanted to help you eliminate a bad tachometer as potential source of your problem. You need the other wire that goes to the ignition controller to be hooked up and tight at the coil negative terminal at all times.
 
Joined
Jun 28, 2008
Messages
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Re: PLEASE HELP!! Mercruiser DIES!!

Yeah i figured it out about what to do from your previous post... but nope its not the tachometer but thanks for your help i really appreciate it! Thanks
 

flabum

Chief Petty Officer
Joined
Feb 17, 2007
Messages
567
Re: PLEASE HELP!! Mercruiser DIES!!

A very common problem is the kill switch. Try jumping the kill switch wires at the dash (where the lanyard hooks to) and see if that helps.
 

Dakota47

Senior Chief Petty Officer
Joined
May 22, 2007
Messages
722
Re: PLEASE HELP!! Mercruiser DIES!!

sell it to your buddy and buy a new boat :rolleyes:
 

bamadave

Petty Officer 1st Class
Joined
Mar 24, 2005
Messages
391
Re: PLEASE HELP!! Mercruiser DIES!!

Is the shift interupt switch disconnected when the cannon plug is separated?
 

RJLeuwen

Seaman
Joined
Jun 19, 2008
Messages
69
Re: PLEASE HELP!! Mercruiser DIES!!

Is the shift interupt switch disconnected when the cannon plug is separated?

No it is not.

That is the next thing he should disconnect seeing that it is not the boat harness causing the problem.

RJ
 

MikDee

Banned
Joined
Jun 6, 2007
Messages
4,745
Re: PLEASE HELP!! Mercruiser DIES!!

Did you check your fuel tank antisiphon valve, & fuel filter? Or maybe the fuel tank vent? Just a few items that come to mind.
 

DayCruiser

Ensign
Joined
Sep 24, 2004
Messages
953
Re: PLEASE HELP!! Mercruiser DIES!!

A very common problem is the kill switch. Try jumping the kill switch wires at the dash (where the lanyard hooks to) and see if that helps.

I was having a similar problem one time and it was the above. A short in the killswitch. Got that from the great mechanics here. Saved me some time and money thats for sure
 

Don S

Honorary Moderator Emeritus
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Re: PLEASE HELP!! Mercruiser DIES!!

Just run it with a jumper wire from the battery POS terminal to the coils + terminal as mentioned a long time ago. This will tell you if you have engine problems, or helm wiring problems which will cut out about half of your random searching.
 
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Messages
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Re: PLEASE HELP!! Mercruiser DIES!!

Yeah i tried that and its still doing the same thing as before. So it cant be anything from the engine up to the helm. So it has to be something on the engine right.... please correct me if i am wrong!!! Like mentioned above it could be a short in the kill switch but does the kill switch go through the cannon plug?
 

Don S

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Re: PLEASE HELP!! Mercruiser DIES!!

You can disconnect that round 10pin harness and the engine will still run with the jumper.
Disconnect the shift interrupt switch and try it again.
 
Joined
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Messages
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Re: PLEASE HELP!! Mercruiser DIES!!

I ran the engine with the jumper and the shift interrupt switch dissconnected and its still having a problem.
 

Don S

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Re: PLEASE HELP!! Mercruiser DIES!!

How long does it run after you start it?
 
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Re: PLEASE HELP!! Mercruiser DIES!!

It depends sometimes 30 seconds, sometimes 10 seconds, and if i am lucky 1 minute.
 

Don S

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Re: PLEASE HELP!! Mercruiser DIES!!

Put a jumper wire across the 2 terminals of the oil pressure switch and try it.
 

Don S

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Re: PLEASE HELP!! Mercruiser DIES!!

The oil pressure SWITCH, not the oil pressure gauge sender. Should be located on the port side aft of the block just above the oil filter base.
 
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Messages
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Re: PLEASE HELP!! Mercruiser DIES!!

Yes i know the oil pressure sender is on the top of the motor on the right side by the distributor. the SWITCH is on the right hand side of the motor right above the oil filter yeah i know but it only has 1 terminal and i have tested it. Its in good working condition.
 

Bondo

Moderator
Staff member
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Apr 17, 2002
Messages
71,082
Re: PLEASE HELP!! Mercruiser DIES!!

it only has 1 terminal

Ayuh,.....

That's the Sending Unit,..... The Switch has 2 wires.......

Keep lookin'....
It's mounted down low, postside, just ahead of the oil filter adapter...
 
Joined
Jun 28, 2008
Messages
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Re: PLEASE HELP!! Mercruiser DIES!!

I know what the sending unit is and the switch is... i work on engines everyday but my engine only has 1 terminal for the switch. I dont know why it just does.
 
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