90HP Johnson Coil

[Miroash]

90HP Johnson Outboard. I noticed that someone changed the coils to a newer style coil; it is supposed to have coil with 2 wires coming out of the back and the single spark plug wire going to the spark plug. But it has coils with a spark plug wire going to the spark plug and then another spark plug looking wire going to the power packs and then a ground wire attached to the mounting bolts. I am only asking because I have a slight miss and was thinking maybe they do not put out the same voltage as the ones recommended for my particular motor. I have referenced the coils that are being used as the coils used on a 1986 90hp model Johnson. Are they the same with the exception of the wire connections?

 

[tashasdaddy]

Re: 90HP Johnson Coil

these are the coil for your motor.
Part Number: 0582106
Description: KIT AY,IGN COIL
Pack Qty: 1
Dimensions: 4.25 x 3.50 x 3.50 (in)
Weight: 0.53 lbs
Equivalent Parts: 0582366,0583737,0584561

this is the coil for the 1986 90 Part Number: 0582508
Description: IGNITION COIL


i would say the 1986 coil is not compatible.

 

[Miroash]

Re: 90HP Johnson Coil

Is it the amount of voltage that makes it non-compatable? it seems to run pretty good with the coils from the 86 model just has a slight mis. It's not that I doubt you know what your talking about, I just want to avoid spending the money for 4 new coils if that is not the problem. Is there a way to verify these coils are the cause of the mis without replacing them? They all have a very good/strong spark, in fact all 4 coils look brand new as do the power packs.

 

[tashasdaddy]

Re: 90HP Johnson Coil

are you using Champion QL77JC4 spark plugs gapped at .030. if not get them in there. other brands are known to cause misfire.

 

[Chinewalker]

Re: 90HP Johnson Coil

Your issue may be the coil(s), but it isn't the TYPE of coil. They are compatible. Find out which coil is misfiring - an inline spark tester may show it. Swap coils around to make sure it's the coil and not the pack or sender. If the problem follows the coil, then you'll know what the issue is...

 

[bustermin]

Re: 90HP Johnson Coil

They all have a very good/strong spark, in fact all 4 coils look brand new as do the power packs.

Since the motor is running ok, with the exception of the mis-fire, I think you should do as TD suggested and verify you have the correct plugs and that they are correctly gapped. I am assuming that you have already done a spark test since you are saying the spark is "good/strong". Also might not hurt to do a compression test (hot & cold), if only to tell you the condition of each cylinder. Another thing to consider, when the last time the carburetors were cleaned and the filters changed. It also could be a little water in the fuel. It may just be time for basic maintenance/Tune-up.