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-   -   502 MPI Stopped running (https://www.offshoreonly.com/forums/general-q/349098-502-mpi-stopped-running.html)

Smitty 08-12-2017 09:28 PM

502 MPI Stopped running
 
2000 502 MAG MPI. Started motor at the ramp. Parked truck and when I got to boat, it had stopped running. Has no spark now. Checked fuses and swapped coils. No change. Possibly the ignition module ? It tried to pop a couple times, but no start. And it is getting flooded as well.

Guesses ??

Thanks

BUP 08-12-2017 10:35 PM

OEM Mercruiser stock ignition set up ? or what set up ?

If stock my money is

Change cap and rotor to new with quality pieces AND THIS BELOW in the link.

I would change out the PICK UP COIL before I would ever change the module. There is testing procedures for both to make sure.

Mercury Quicksilver 811639T - Coil

BUP 08-12-2017 10:39 PM

And its called the pick up coil for stock Merc ignition

AllDodge 08-13-2017 06:48 AM

2 Attachment(s)
I would try to bypass/check the lanyard stop switch (kill switch). 12V at the coil


And it is getting flooded as well.
Also check fuel pressure

Smitty 08-13-2017 08:16 AM

It is all OEM ignition. I will try your suggestions.

It is a twin set up so it is not the kill switch as it is a twin setup, and other motor runs.

AllDodge 08-13-2017 09:30 AM

OK, have 12V at the coil?

Smitty 08-13-2017 11:16 AM

Tried coil from other motor, no difference. Just got a new cap, rotor, and pickup coil. Fingers crossed as it is finally a perfect day here in Chicago.

BUP 08-13-2017 11:21 AM

pick up coil is my guess here. . But were did you buy that on a Sunday and whom had that in stock ?... I have them but I find many other boat places do not ever stock them.

if you have the proper service manual there is flow chart testing for all the ignition related sides and parts plus install procedures.

IMPORTANT NOTE. before starting the job - Unhook your battery to that engine and or make sure no power to the engine. Perko switch or however your app is set up for battery power cut off.

AllDodge 08-13-2017 11:21 AM

If your not getting 12V to the coil it will fire, old or new

12V should be found on the red wire with the key on

BUP 08-13-2017 12:07 PM

I'm taking it as, he had no spark at the spark plug wires and or spark plug(s) ? correct ?

Sealed inline spark checkers are one darn great tool to have. Just saying and make sure you have the sealed ones. open spark in the engine compartment after cranking with no start means a lot of fuel vapor to be had / open spark and fuel vapors = possible boom


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