Coil question

[Robj]

I am working on making one 6 hp Johnson from two motors that I have. They are the points ignition vintage. Both engines have no spark, and I think it is odd that I have 4 bad coils (2 per engine). Does anyone know the process for checking these? Want to make sure the coils are shot before I go out and buy new ones.

Thanx for your help and have a great day,

Rob.

 

[tashasdaddy]

Re: Coil question

model numbers, and year, not uncommon for those to be bad. they dry out and crack, thus shorting out. picture of them.

 

[Robj]

Re: Coil question

Thanx TD. It is probably late 70's vintage. OMC used this coil on many of their engines. Just wanted to know if anyone knew the specs so I can meter them before throwing them away.

Thanx and have a great day,

Rob.

 

[R.Johnson]

Re: Coil question

You could check with your dealer to see if he has a coil tester before throwing them away. If they don't have surface cracks', they may be alright.

 

[F_R]

Re: Coil question

Using an ohmmeter, check continuity between spark lead and ground wire. Should be several k-ohms.

Then check continuity between points lead and ground lead. Should be Zero ohms with points closed and about an ohm or less with points open. You need a good meter to register an ohm or less.

High voltage leakage such as through cracks or between the secondary windings require a coil tester.

But if they aren't cracked or look like they are covered with drops of dried-up sweat, and pass the ohms test, chances are they are good to go.

 

[Robj]

Re: Coil question

Thank you for all your replies. I will check with a meter as F_R suggested.

Have a great day,

Rob.