Mercury Mariner 75 No spark at any of 3 coils

jmburock

Petty Officer 2nd Class
Joined
Aug 25, 2005
Messages
174
I have a 1989 Mariner 75hp 3 cyl (SN# OC170850). Had been running well until the end of the season although hard to start cold at times. Now no spark at any of the three coils w/ spark plug tester. Tested the stator ohms: at spec of 1.0 ohms. Starter turns over well, battery at 100%, disconnected yellow/black tilt kill switch w/ no improvement. I am leaning towards the switchbox or regulator?? any thoughts? could this be the trigger or stator (even though within proper ohms)? will do anything to not take it do the dealership if possible.

thanks in advance, Jeff in Bristol, RI.
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Mercury Mariner 75 No spark at any of 3 coils

Not the regulator. Different system. I'd advise taking it to a Merc dealer. They can quickly diagnose it and replace the offending part. If you guess wrong, you bought the part. No returns on electrical parts unless they're defective. I see time and time again where people first guess one part, then another, and before you know it they have replaced the whole system at a price of several hundred dollars when they only needed one part. Heck, it could be anything from a bad ignition switch for around $30 to a bad stator at several hundred dollars. In at least half the cases I see where the customer tried fixing it themself, they could have saved hundreds by taking it to a dealer in the first pace.
 

jmburock

Petty Officer 2nd Class
Joined
Aug 25, 2005
Messages
174
Re: Mercury Mariner 75 No spark at any of 3 coils

You're probably right about this. I did isolate out the regulator, so I am assured it wasn't that. It has the red stator. I believe this is known to cause some problems in the past. The stator has the correct ohms but I can't test it running because It won't even spark let alone run. Any other things to sort out before breaking down and taking it to a dealership..thanks. and my wife agrees with the bringing it to dealer part...:$
 
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