Info on testing stator, trigger, and switch box?

Jamz3333

Seaman
Joined
Oct 12, 2010
Messages
72
I have i believe a 1983 50 hp mercury 4 cylinder engine and we had it running about a month ago and I took it from the my grandpas garage to my brothers shop (maybe a quarter of a mile away and now I have no spark to the plugs. Not sure what could have changed. If I could some input it would greatly appreciated. I am planning on checking it out tomorrow.I have read stuff about checking stators, triggers and switchbox, but i just some clear information about how to test each of them or where to start first.
Thanks.
 

Jamz3333

Seaman
Joined
Oct 12, 2010
Messages
72
I tested the stator and low side reading was 8080 ohms. High side was 150 ohms. Low side is high from what I read. Is stator bad?
 

Craigbbbbb

Cadet
Joined
Mar 8, 2016
Messages
26
I have a '69 merc 1000 and the stator is for recharging the battery, the spark comes from the coil and the battery I thought, can someone tell me if this is correct? Mine is thunderbolt breaker less battery ignition! Did the battery cables get hooked up backwards or did the battery get unhooked while it was running? Check your switch box too! Should have 12v with key on and 12v on a different terminal with the key off, I don't know what your serial number is so its hard to know your exact wiring diagram! And you should have 9.5 volts while cranking too I believe! You should be able to bypass the distributor and make the coil spark if the switch box is good, coil doesn't go bad as often as a switch box. Post your serial number maybe someone has the testing procedure and specifications for your coil, stator and switch box
 

Jamz3333

Seaman
Joined
Oct 12, 2010
Messages
72
My switchbox P/N is 332-5772A1. My stator is 398-5454A21. I think it might be the switchbox. I used a multimeter and touched one lead to the terminals of the trigger (without trigger hooked up and with trigger hooked up) and other lead to ground and get a reading of 16,000 something OHMS. Would this mean the switchbox is shorted out?
 

merc850

Commander
Joined
Jul 7, 2010
Messages
2,050
Before you run around in the wrong direction that 1983 has alternator driven ignition, no battery is needed to fire ignition but you should have a good battery to spin the motor fast enough (200+ rpms) for it to start. A quick ignition test is to hook a timing light to any spark plug and see if it flashes.
 
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Jamz3333

Seaman
Joined
Oct 12, 2010
Messages
72
I don't think it's even getting fire to the coils. Would a timing light still help?
 

Craigbbbbb

Cadet
Joined
Mar 8, 2016
Messages
26
Thanks for clearing up about how the ignition works! It it is alternator driven then it seems like it could be the stator, switch box, or coil! stator and coil should be able to test with multimeter but I don't have the manual so I don't know the specifications! You can get the online manual that is printable for 5$ I think, and then just print any pages you need or read it off the computer while you work, definitely not as convenient but cheaper
 
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