Mercury outboard coil recalls

raymor

Seaman
Joined
Jun 24, 2007
Messages
60
Has anyone heard of recalls on Mercury 115hp 4-stroke for bad coils. This is the second coil that has gone bad on me. Year of the motor is 2004. This time is is only half the coil that is intermittent which is misfiring the #3 plug.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
Re: Mercury outboard coil recalls

This coil is not divided internally, it is a single coil with two outputs. Only way it could act up is if plug wire connection was internally failing. The only problem I have seen with these coils is wire burning into inside plug boot. If coil was failing it would also affect cylinder #1. Swap the #1 lead with #3 and see if problem follows.....
 

raymor

Seaman
Joined
Jun 24, 2007
Messages
60
Re: Mercury outboard coil recalls

Faztbullet, thanks for the reply. The plug wires coming out of the coil look like they are sealed into the coil. Can I break the seal and pull the plug wire out of the coil or are they part of the coil? I guess what I'm saying are the plug wires part of the coil?
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,589
Re: Mercury outboard coil recalls

Yes they are part of coil, inspect the boot that snaps onto sparkplugs as this is where it fails...
 

raymor

Seaman
Joined
Jun 24, 2007
Messages
60
Re: Mercury outboard coil recalls

I will do that tomorrow Faztbullet. I did look into the boot as you had said in another thread they do fail there. Looked nice and clean, but will look a lot closer this time. There is also a boot on the coil end of the spark plug wire does that come out of the coil and can I have a spark plug wire made up if it does?
 

raymor

Seaman
Joined
Jun 24, 2007
Messages
60
Re: Mercury outboard coil recalls

Faztbullet, I checked out the plug cap and could not see anything wrong. Started engine and moved the plug wire around and it seems to get better if I **** the plug to a little bit of an angle. Is there some trick to fixing this plug wire? For now I just dropped the plug gap down to .30 thousant from .40 thousant. Seems to run better now and no break up under way at low RPMs.
 

raymor

Seaman
Joined
Jun 24, 2007
Messages
60
Re: Mercury outboard coil recalls

Faztbullet thanks for your help in this matter. Replaced all the plugs and it fixed the problem. Must have had more than one bad plug as swapping plugs around the problem did not seem to follow the swap. These are nkg Lfr6a-11 plugs @ $7.29 a pop which is a little on the expensive side it you ask me. Don't think I have ever seen a failure like this in plugs in my 50 years of boating. I have had failures right out of the box, but these were pretty clean looking plugs. Is there another plug you can put in as a replacement for the NGK LFR6A-11??
 
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