1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

[rs2k]

I put the boat into the water and fired up the engine. It ran fine for 5 seconds and then stopped. The engine is not getting a spark. I hooked up an induction timing light off of the coil and am not getting anything. What could have worked for 5 seconds and then stopped?

How can I test the power pack?

How can I test the coil?

 

[patrick4266]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

that should have a amplifier, pull off the wire from the amp that goes to the points, turn on the key, ground it out. It should spark.

 

[rs2k]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

Where is the amplifier?

I just tested the coil.

I get 1791 ohms from the primary to the secondary coils and I get 0 - .2 ohms from across the primary terminals That doesn't sound right to me but I don't know what it should be. I also found a small crack under the coil in the plastic casing.

 

[patrick4266]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

the amp is a square box on the back of the motor, you cannot miss it.

 

[bigpoppakdog]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

does this have an ignition safety switch? It's located to the right of the rectifier just above your power pack. Is there a jumper wire from terminal 7 to terminal 9?

 

[rs2k]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

I don't think so. There is nothing hooked up to terminal 7.

 

[rs2k]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

the amp is a square box on the back of the motor, you cannot miss it.

I get a spark when I disconnect the wire from the bus and reconnect it to the bus. I think it may be coming from the power pack, though.

 

[bigpoppakdog]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

i've heard different opinions on testing an ignition coil, been told that you can test them for resistance, and have also been told that you can't test them like normal auto coil. I guess the easiest way is to have a DVA meter and test the blue wire coming out of the pack. I had two different ignition coils earlier this summer and when I did an ohms test, they read completely opposite from each other. Also when you turn the key on check the purple wire with a meter and see if you have volts going into the pack.

 

[rs2k]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

I'll replace the coil and report back with the results.

 

[rs2k]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

It's running again. I'm heading out to the lake to see how she runs. I replaced the coil but still couldn't get it to start. The mechanic where I got the coil told me that these engines have an spring under the fly wheel that ground the ignition when the motor runs backwards. He said that sometimes the springs jam and it will cause the motor not to start. Thinking this was a possibility I lightly tapped on the fly wheel a few times with a metal bar. After that it fired right up.

Maybe it was this spring that was causing the problem, or maybe tapping on the engine caused something else to start working. Could the Pulse box be intermittent?

 

[bigpoppakdog]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

this spring could cause intermittent start and stop.

 

[rs2k]

Re: 1972 100HP Evinrude 100293 worked fine until I took it to the lake - NO SPARK

I think it was the spring. I ran 11 gallons through the engine with no trouble at all, but I did have a bit of trouble when I tried to flush the engine back at home.
I didn't see any water coming out of the top holes of the engine but I thought this was just because the thermostat wasn't open. The overheat horn sounded after about a minute and I shut it down. It's odd that I was able to run the engine for three hours without trouble. I'll post a separate thread for this new problem.