Mariner 40 (2cyl) problems with ignition coils

[mattclubb]

On the stator plate there are three coils, as far as I know these are<br />One for auxiliary power supply to a radio etc.<br />One radially orientated for ignition<br />One circumferentially orientated for ignition.<br /><br />There was a problem with the circumferentially orientated coil and so I rewound it with almost identical wire and turns etc.<br />Connections on this coil are one to ground (under the metal laminates) and one to a brown wire from the ignition.<br />Well I've done all this but there is not a peep from the engine, <br /><br />Would it make a different if this coil is wired in the wrong way round???? i.e. have I 'grounded' the wrong wire?!<br />Could this be the source of my problem???<br /><br />ALL help much appreciated,<br /><br />Thanks<br /><br />matt

 

[Paul Moir]

Re: Mariner 40 (2cyl) problems with ignition coils

I don't know your engine, but if you wind a coil 'backwards' the pulses from it will be negative instead of positive (or vice versa). At this stage I would guess reversing the leads to correct polarity would be worth a shot, but sending the wrong polarity to the ignition module may have blown it. How certain are you that you wound it backwards?

 

[mattclubb]

Re: Mariner 40 (2cyl) problems with ignition coils

The engine is approx 1991.<br />not at all sure that the coils are wound incorrectly just thought that the end connectors may have been connected the wrong way round when I wired it back in.<br />Would the ignition module have blown? I thought it was Alternating Current anyway???<br /><br />matt

 

[Paul Moir]

Re: Mariner 40 (2cyl) problems with ignition coils

Sorry, I don't know your engine's ignition system so I'm being very general. _If_ the coil works the way I'm imagining it to, it would be generate a pulse series rather than alternating current. I'm also not certain whether that would damage your ignition module. It may be protected against it, or it just may have taken it in stride. Chances are it's fine. <br />Seeing that your rewind is neat and has the same number of turns as the original, like you I don't see any other explanation. You could put an analog meter set to DC on the coil and see which way the needle swings when you crank the engine to confirm that it is putting out a DC pulse rather than AC. If it is AC, the needle should not move or swing both ways equally.<br />Sorry I couldn't be more useful. Hopefully someone with more experiance can help.

 

[nedrah]

Re: Mariner 40 (2cyl) problems with ignition coils

hey matt I think we have the same engine 40hp mariner with gray cover.. My sparks plugs are a ngk br8hs. Do I have to gap the new plugs. If so what gap do I use. I just bought the boat and the previous owner changed the plugs but I am sure he did not gap them. Thanks

 

[rickdb1boat]

Re: Mariner 40 (2cyl) problems with ignition coils

nedrah <br />Your spark plug gap is .024 B8HS

 

[dpminc]

Re: Mariner 40 (2cyl) problems with ignition coils

The charging(aka exciter,charge,power,source etc)coil produces ac current that is rectified to dc within the ignition module. This dc current is then used to charge up a storage capacitor. The trigger coil(aka pulser,timing coil etc) produces a small amount of ac voltage(wound for a very fast build-up)that is monitored by control electronics, and used to trigger a SCR (electronic switch) that closes the output circut from the capacitor to the ignition coil (aka pulse transformer, secondary coil, final coil etc)dumping the stored charge of the capcitor into the primary windings of the ign coil causing a rapid building of electomagnetic flux around the secondary winding, which produces a high voltage to jump the spark plug gap. By mimicing the wire size and windings ratio you should get a close voltage, however, there is very little tolerance for voltage outside of design parameters, and this may be throwing off the elec in the module. You should be able to read ac voltage coming fron the coil(that you repaired) outputs with an ac voltmeter (x 1.414 to convert to peak v). See how these compare to the factory numbers in the manual. Can you not find these coils?? I would think replacement with used ones would be easier. If you have voltage at the charge and trigger coils, check for voltage at the ignition coil primary lead.If no voltage, the module is probably bad. Be sure to isolate any kill circuts when testing so a bad kill or saftey switch is not the cause of no spark. For used parts, I use www.tcoutboard.com