should i change coils too ???

72 mako 19

Seaman Apprentice
Joined
Sep 15, 2002
Messages
39
93 johnson 88 special... i am changing the power pack because a cylinder dies every now and then...<br /><br />my question is ... should i change all 4 coils too?..
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: should i change coils too ???

Ahoy, Mako.<br /><br />I don't generally believe in changing parts that aren't broken unless they are nearing a predictable life cycle failure.<br /><br />If you eliminated the coils as the cause of your trouble before buying a new powerpack, leave them alone. If you are changing the powerpack as a diagnostic exercise wait and see what happens.<br /><br />Good luck. :)
 

Carphunter

Commander
Joined
Aug 11, 2002
Messages
2,061
Re: should i change coils too ???

Whats happenin Mako!<br />I had a small crack in one of my coils that was barely noticeable. When I placed the cover on the motor, the engine would idle down. Found out that the coil was "arcing" to the latch on the cover.<br />I have a 1981 Johnson 115. I never would have thought to change that coil had I not tried to put the cover on while the engine was running. The coils didnt cost much, so I just changed them all. Happy I did. So to answer your question, it certainly wouldnt hurt to change them all........the peace of mind is priceless.
 

james roach

Petty Officer 1st Class
Joined
Nov 17, 2002
Messages
216
Re: should i change coils too ???

Dont change the pack change that coil. 20 bucks spent is better than 100 anyday. Carry a spare coil also.If you were losing more than 1 cylinder then change the pack.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: should i change coils too ???

Don't change the coil yet.<br /><br />Swap it with the other one. If the trouble swaps cylinders, then change the coil. If it doesn't, change the powerpack.<br /><br />More money is wasted changing parts that don't need changing than is spent replacing parts that are broke.<br /><br />Good luck. :)
 

ledgefinder

Ensign
Joined
May 2, 2002
Messages
916
Re: should i change coils too ???

What JB said, plus the bad coil (if bad) may be what's causing you to burn powerpacks. If the charge in the powerpack has no where to go (due to open circuit in coil), it tries to jump the insulation.
 

BillP

Captain
Joined
Aug 10, 2002
Messages
3,290
Re: should i change coils too ???

I have no idea what is happening but do have some comments:<br /><br />Coils are one item that can go with age. Heat and moisture can do damage without running the motor or using the coil. If you see cracks in the coil covering it is definitly time to change before they die...could be years or days for failure when cracked. <br /><br />When you say "dies every now and then" does that that mean at idle or high speed? Are you getting backfires (electrical probs are generally backfires)? It it a sudden stop or gradual reduction to stop (likely fuel delivery)? Is it dropping a cyl as if you pulled a plug wire off all at once? You have swapped plugs and checked compression right? Will it stop running when the choke is on? Checked all wiring and connectors?<br /><br />If it dies at idle then the problem could be as simple as a cold running engine (tstate out or bad and rough running or coughing engine would be happening first).<br /><br />So why do you think it is coil or ppack related?<br /><br />One last thing...I personally would(do)change coils and ppack on a 10 yr old motor (and I carry a spare ppack aboard). Like already posted, one bad electrical component can make a good part go down. It isn't worth the hassle to have motor problems out on the water...but then again SeaTow is available for a 100 bucks these days. :D
 

james roach

Petty Officer 1st Class
Joined
Nov 17, 2002
Messages
216
Re: should i change coils too ???

I had the same scenario last summer with my 1987 200 HP Johnson. It sounds like all of your coils are firing while idling and once under a load one is breaking down. When it breaks down you lose fire to one cylinder. This can cause the RPMS to surge on and off or just make the motor run about 500 less RPM at wide open throttle. My motor displayed the same problem before I changed the coils and I have not had another problem since. I will say that I have owned 2 OMC V-4's and my present V-6 and ALL 3 have needed coils replaced while I owned the motor. I had a pack to fail on my 200 HP and I lost 3 cylinders not 1. If you are losing only 1 start with the coils. Moisture is a killer for these electrical parts. I always carry spare coils, plugs, thermostats and usually a spare pack. BTW I hope you have a manual.<br />Thanks
 
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