Coil testing '59

[Itec01]

I have a 1959 Johnson Seahorse 18hp Model FD-13R and have had problems that have got me bummed out.<br /> The next step in my trouble shooting process is to test the coils. <br /> Can anyone tell me how to go about this test.<br /> I have ordered a service manual but it'll be a number of days until I recieve it and I can't wait that long.

 

[fireman 757]

Re: Coil testing '59

First, check for spark at the plugs. See if it will jump spark 1/2" to the block (of course the plugs are pulled for this). If you have good spark then it is not the coils. If you have spark to one cylinder and not the other swap the coils and repeat the process. If it reverses the spark then you know you have a bad coil.

 

[Joe Reeves]

Re: Coil testing '59

In addition to Fireman's post, you can check the coils for continuity with a ohm meter to see if there might be a break in their internal wiring.<br /><br />There should be continuity between the prong (the prong is inside the coil that the spark plug wire is plugged into) and the coil ground wire, and also between the prong and the coil wire that leads to the points. The wires must be disconnected for this test. If you do not obtain a reading from both wires, there is a break in the coil windings, and whether the coil fires or not, it is faulty and should be replaced.