1978 90hp Mercury Ignition Coil Test

psimonee

Cadet
Joined
Jul 15, 2003
Messages
8
Trying to troubleshoot ignition problem and need help. I do not have spark. I tried reading with ohms meter the two terminals on the ignition coil. gnd and conv. The result is a closed circuit ( 0 ohms ). Is the coil burnt? Should I have a small reading?<br /><br />thanks.<br />simon
 

mellowyellow

Vice Admiral
Joined
Jun 8, 2002
Messages
5,327
Re: 1978 90hp Mercury Ignition Coil Test

swap coils and see if no spark follows.<br />good luck,<br />M.Y.
 

psimonee

Cadet
Joined
Jul 15, 2003
Messages
8
Re: 1978 90hp Mercury Ignition Coil Test

this motor has a single ignition coil feeding distributor. Sure do wish I had an extra one to swap, but don't.<br /><br />simon
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: 1978 90hp Mercury Ignition Coil Test

Sounds like it's dead shorted out. There was a suggestion to take it to a lawnmower shop and have them test it. Sounds like a good idea to me. You should not be reading zero from all terminals to ground. Betting it's shot!!<br /><br />This may work, using an Ohmmeter touching each side terminals looking for 0.75 to 0.81 ohm of resistance. Then go from the primary (Spark Terminal) to each small terminal, should read 10,000-11,000 ohms. If not within readings, replace.
 
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