Ignition coil specs.

7mm

Seaman
Joined
Nov 12, 2017
Messages
55
I just purchased a Sierra ignition coil for a 1986, 2.5L, OMC. It tested 5 resistance ohms right out of the box. Is it defective or something special for that model???
 

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
if you're doing the test correctly, defective

what does your meter read for ohms when you touch the 2 leads together?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,295
why do you think its the coil? coils rarely if ever go bad

if your motor isnt running, did you service the points?
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
Not uncommon for the primary side of coils to read low resistances. If you understand how a coil works, there are very few windings on the primary side of ignition coils and many many winding on the secondary side to output thousands of volts to jump the spark plug gap. JMHO
 

7mm

Seaman
Joined
Nov 12, 2017
Messages
55
The dealer where I purchased the coil agreed that the coil was defective. He took another off of the shelf and it tested 1.5 ohms. In spec. The old coil in the boat was out of a truck and tested way out of specs.
 
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