dduane
01.05.2021 8:52:40
The video below describes how to check vintage Johnson Evinrude OMC outboard ignition coils for functionality.
See full version: Test Ignition Coil
The video below describes how to check vintage Johnson Evinrude OMC outboard ignition coils for functionality.
If your coil is bad you can buy another Sierra International 18-5181 Ignition Coil from Amazon at http://amzn.to/2frFGJ8
First , in order to properly test the coil, you need to remove it from the ignition plate.
The first step is to do a Ohms test to see if the coil is good before going on to the visual internal ferrite core inspection.
4. The string stranded packing type of tape is used to hold the two ferrite cores together. Sometimes this gets dirty and looses its adhesion so the technician recommended to add the silicon to hold the ferrite like before and to add a couple of Super Glue Gel drops where they ferrite core halves meet. You could also add the string tape if you would like for added comfort.
The technician at CDI gave me some pointers on how to check a coil and I thought I would pass them on.
On the voltmeter, the dial should be turned to OHMS. For an outboard motor, set the range to 200. more
For the health of the coil, do not load the coil. Moreover, excess heat, vibration can damage the coil easily.
Erratic sparking may occur in the cylinders at the wrong time as well. [links]
Keeping your boat unused for a longer period of time can cause bad plug health. This includes corrosion of spark plug, even fouling. here
Note the multimeter's reading. If there is a second spark plug tower for coils that fire two spark plugs, move both meter leads to the primary and secondary tower pair for the other spark plug. Resistance should be between 225 ohms and 325 ohms for all motors except for 25-horsepower and 35-horsepower two-stroke motors built between 1995 and 1999. On these motors, the resistance should be between 2,000 ohms and 2,600 ohms. [links]
Select the "resistance" scale on the digital multimeter. Disconnect the secondary coil wiring and connect one multimeter probe to the coil primary connector tower and the other to the adjacent secondary tower. [links]
Confirm all connections and readings if the coil tests out of specification. Replace the ignition coil if either the primary coil readings or secondary coil readings are well out of specification and all test connections and conditions were conducted properly.
Most boaters don't have the equipment a professional has to test the coils on a Johnson outboard motor. What most boaters do have is a digital multimeter. When you talk about "the coils," you are talking about the primary and secondary ignition coils and you have to test both, using the multimeter. If the readings on the digital multimeter are outside of the limits established for the particular motor, take steps to ensure that the test was conducted correctly and retest the coil.
Retest the primary coil if tests are out of specification, making sure that only the wires or connectors were probed. Make sure the ground was unpainted. If you can locate no outside cause for the readings being wrong, replace the coil. [links]