Coil question

[jcrigan]

I have an 1977 Evinrude 4hp motor with the cd ignition. Was wondering what these coils should read with an ohm meter. The secondaries both read at 1.5 kohms. I have another set of coils where the secondaries read at 0.253 kohms. So, what’s normal for these?

[fleetwin]

Well, the newer style coils read about .253kohms/253 ohms. If both of your older coil secondaries read 1.5kohms, I would say that is in the ball park for older coils, especially if both coils have similar resistance readings. . The primaries should read about .1 ohms. Are you having a spark issue? Or, are you just checking things out as a routine service?

[jcrigan]

I recieved this motor free from a scrap yard. Never worked on a CD ignition before. The secondary resistance is what got me confused. On points systems the resistance is usually 3.5k and above. The motor does have starting issues. Usually needs the choke out to start and needs several pulls. I will swap out the coils with these others and then see how it will run.

[frankr]

You can’t compare CD coils with the old points/condenser coils. Apples & oranges as they used to say.

[jcrigan]

Yes they are different.

[fleetwin]

I really don’t think you have two bad coils….Sometimes, you have to advance the throttle past the “start” point on the cowl to get them to start easier. Make sure the choke is closing fully and staying that way while cranking, it doesn’t have much of a “detent” to keep it closed… Does the engine run OK once started/warmed up?

[jcrigan]

It runs fairly well now that i have the carb adjusted. Still, when cold it still needs a few extra pulls. I am amazed at how long this engine runs after disconnecting from the fuel tank.

[fleetwin]

jcrigan wrote:

It runs fairly well now that i have the carb adjusted. Still, when cold it still needs a few extra pulls. I am amazed at how long this engine runs after disconnecting from the fuel tank.

I seem to remember issues like this with later 4hps…The choke plate may have relief hole(s) that are a bit too big. I hesitate prescribing plugging one of the holes, you sure don’t want solder or whatever falling out and getting sucked through the reeds. It is not a good idea to attempt removing the choke plate either….You don’t want those screws (that are peened over now) to fall out and go through the engine either.
And yes, seems like forever to stall with the fuel hose removed….
Try advancing the throttle past the “start” position for cold starts…

• This reply was modified 3 years, 11 months ago by fleetwin. Reason: addition

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