1985 Merc 50 4 cylinder - please help no-start (with history)

barrythedude

Seaman Apprentice
Joined
May 13, 2006
Messages
32
The symptoms: running great, start like a champ, one day went out, whirled for a while, but started, no other trubbles that day. Next week - no start - tried for 2 hours, whirl, but no start.

To date:
- Got a manual and wire schematic
- New plugs (needed anyway)
- From the from remote, tilt/trim works, choke snaps shut, starter engages
- a 5 dollar spark tester inline shows no spark (at any of the 4 coils)
- checked all wires and tightened where necessary
- There is a fuse in the cover bag but I am unaware of a fuse anywhere (can't find if there is)
- I removed the black w/yellow wire for the mercury switch, no change
- manual I have says has to be 210-320 v from a wire (really?) I only showed 40V

Now I am bamboozled, I am thinking stator or trigger plate, perhaps disassemble the remote handle and see what the harness connector looks like, but I have never done that. both unwelcome to me. Are there any other tests or troubleshooting any of you can suggest? End of season here, but taking the boys out for one more fishing trip before they are too old and cool for dad would sure be dandy. Serial number is 7221339 and I sincerely thank anyone in advance who answers. I love this forum!
 
Last edited:

verado7

Chief Petty Officer
Joined
Apr 28, 2009
Messages
511
Re: 1985 Merc 50 4 cylinder - please help no-start (with history)

disconect stator wires and check the voltages while cranking - it will be either stator or switchbox - if they have any age on them its highly recommended to do both .
 

barrythedude

Seaman Apprentice
Joined
May 13, 2006
Messages
32
Re: 1985 Merc 50 4 cylinder - please help no-start (with history)

I thought Stators almost never gave problems, but would slowly let you know something was wrong without a complete stop.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,930
Re: 1985 Merc 50 4 cylinder - please help no-start (with history)

Remove the blk/yel from pack and retest, if you now have spark problem in kill switch.ign switch o harness. If still no spark ohm/DVA test the stator,trigger and switchbox...
 

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barrythedude

Seaman Apprentice
Joined
May 13, 2006
Messages
32
Re: 1985 Merc 50 4 cylinder - please help no-start (with history)

The wire you describe is the mercury switch, I have tried disconnecting that - voltage never gets above 40V on my ohmmeter
 
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