Coil problem again

Rinker85

Petty Officer 1st Class
Joined
Aug 29, 2010
Messages
207
Can someone please give me test procedures to make sure the correct voltage is going to the coil under running conditions?
I am on my 3rd coil in 3 years. Every summer since 2017 I have replaced the coil in late July or August. Same symptoms.. Boat runs fine for 40 minutes then all kinds of power problems. I replace the coil and the problems disappear for 1 year.

The points are good. Plugs are good. The Dwell is fine as well as the timing. What could be ruining the coil the past 3 years. I've never had this problem before. I've had the boat since 1992. Its a 1984 2.5 L OMC.

Thank you
 

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
What coil you using? Go to Napa and get a 1C14SB coil and run it direct from the ignition, bypassing the resistor wire. That NAPA coil runs at full battery voltage, it is in a heavy steel can and lasts for years and years.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,752
you cant run points and bypass the ballast wire. you will burn the points up.

a bad condensor would cause what you are seeing.
 

Rinker85

Petty Officer 1st Class
Joined
Aug 29, 2010
Messages
207
What coil you using? Go to Napa and get a 1C14SB coil and run it direct from the ignition, bypassing the resistor wire. That NAPA coil runs at full battery voltage, it is in a heavy steel can and lasts for years and years.

I'm using a Sierra Marine 18-5437 coil
 

Rinker85

Petty Officer 1st Class
Joined
Aug 29, 2010
Messages
207
you cant run points and bypass the ballast wire. you will burn the points up.

a bad condensor would cause what you are seeing.

I replaced the coil and it runs just fine once again. I'm going to test the resistor wire next. As far as the points and condenser I replace them every spring. Could something be causing the condenser to go bad which would cause the coil to act up?
 
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