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COILS on a 56 Johnson 30hp

J

johnyboy

Contributing Member
" I think I have some bad coil

" I think I have some bad coils here. With the lead that connects to the points disconected from the points, and using an ohm meter I am showing 0 ohms to block/ground ..... am I correct or is this normal? "
 
Probably should be more clear

Probably should be more clear

0 ohms from the lead from the coil that is supposed to connet to the point to block/ground
 
" Johny..... Checking the cont

" Johny..... Checking the continuity of the ignition coils....... Have the ohm meter set to High Ohms.

Remove the primary wire from points. Remove the coil ground wire. You do not want either of these wires touching anything.

Connect the black lead of a ohm meter to the spark plug boot terminal, then with the red ohm meter lead, touch the ground wire of the coil.

Then touch (still with the red lead) the primary wire. You should get a reading on both touches (contacts). If not, check the spring terminal inside the rubber boots of the spark plug wire.

If there is no continuity between the secondary circuit (spark plug) wire and the primary or ground, remove the coil from the armature plate, then check the continuity directly between the prong within the coil (prong that the plug wire presses into) and the primary and ground.

Poor or no continuity of a coil (or plug wire) is one reason for weak spark, s/plug fouling, or no spark.

Joe (30+ Years With OMC) "
 
" Use a MERCATRONIC tester for

" Use a MERCATRONIC tester for coils.The #1 cause for poor starting is weak coils. They look OK and you have spark when laying a plug on the block,It takes much more voltage to fire a plug when the air/fuel is compressed to 100psi. "
 
Thanks Joe. I tested this way

Thanks Joe. I tested this way and that way. Just about every way possible except to see if there was continuity to the plug wire.

I then stuck it back together to see if I had any spark thinking I may have just had a bad connect on something. I will make those checks my project for tomorrow afternoon (east coast guy and its getting about time to put the toys away).

Did Radio Shack have that adapter?
 
Thanks sparky. Don't have

Thanks sparky. Don't have that tester but if I cant get past it any other way I will bring them to a dealer and them put them on a mercatronic.
 
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