1984 Mariner 9.9C - Ignition Coil Spark Test

cchildr84

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Ok so I recently within the last three weeks or so spun the hub on my prop while out on the water and had to putt back to the dock. So I ordered a new prop. When it came in I put it on and then put the motor in a clean trash can of water to test it out. During the test trial the motor started only twice and both times it died out immediately. So my first though was that it was flooding, so I replaced the plugs, all the fuel lines, and filter. After that tried to start again and nothing, pulled the plugs and they were bone dry. The primer bulb got hard as it is supposed to. I pulled the carb and everything appeared to be clean and all passages clear. So I did a compression check, both cylinders were between 120 & 125. Then I did a spark test, and I wasn't getting any spark. Now correct me if I'm wrong, but the spark test is pretty simple process, in which you plug the tester in the wire boot and clip the alligator clip to the block correct? Thats what I did and wasn't getting any spark. For those of you familiar with this motor and the length of the wires on the coil you know that the wires are rather short so its somewhat difficult to get the tester clipped to the block. Please let me know if I'm doing something wrong. I have a new coil on order and it should be here tomorrow. See picture below of the tester I am using. I set the gap to just under 1/2". Your help is appreciated.

spark tester.jpg
 

jackd1023

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Re: 1984 Mariner 9.9C - Ignition Coil Spark Test

1/2 inch sounds huge for the gap, I usually have it set 1/16. I would check kill switch also. Do you have a manual? Serial number?
 

cchildr84

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Re: 1984 Mariner 9.9C - Ignition Coil Spark Test

1/2 inch sounds huge for the gap, I usually have it set 1/16. I would check kill switch also. Do you have a manual? Serial number?

No, I have no manual. I've read in several forums that 7/16" gap is used to determine the strength of the spark, doesn't make it right though. Serial plate reads as follows 9.9M 682C-S049356. With regard to the kill switch, I did a test with the swith disengaged/un plugged as well and still got no spark.
 
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Re: 1984 Mariner 9.9C - Ignition Coil Spark Test

Try disconnecting this bullet connector

10.02.2013-15.57.png
 

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cchildr84

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Re: 1984 Mariner 9.9C - Ignition Coil Spark Test

Try disconnecting this bullet connector

10.02.2013-15.57.png

Is "F" the kill switch, and "C" the power pack? This is a manual start motor. The Kill switch only has to wires. One running to the power pack connected via bullet connector, the other grounded to the block. As stated above I disconnected the bullet connector from the kill switch to the power pack and still got no spark. Am I doing it wrong?

Compression is excellent 120+ PSI in each cylinder. The motor was running fine before I switched out the props. This motor has never given me a hint of a problem.
 
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cchildr84

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Re: 1984 Mariner 9.9C - Ignition Coil Spark Test

See diagram below for the ignition system on this motor.

Ignition.jpg
 
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Re: 1984 Mariner 9.9C - Ignition Coil Spark Test

C is the power pack F is the stop switch, different from the Emergency stop switch but uses same circuit. Check all of the black wires on the power pack make sure they are securely to ground. If you can eliminate the black wire that provides the path for grounding out the switch box you will eliminate the ess and the stop switch. After that you will have to determine if the pulser coil and capacitor charge coil is defective...DVA needed.
 

cchildr84

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Re: 1984 Mariner 9.9C - Ignition Coil Spark Test

My motor doesn't have an emergency stop switch. Just the standard kill switch. I just find it odd that out of the blue it stops starting. It sat up for 5 years one time, and after replacing the impellar prior to starting, it started on the second pull. This is very strange for this motor. I'm sure the issue is something simple, I just haven't tracked it down yet. The carb was rebuilt about this time last year, so I feel confident it's not a fuel delivery issue as it has been running great. Who knows, if replacing the coil doesn't work I suppose Ill just take it to a shop.
 

cchildr84

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Re: 1984 Mariner 9.9C - Ignition Coil Spark Test

Well, my new coil came in on Thursday, I got new plug boots yesterday, put it all back together and it fire right up. So with all that said I'm not for certain that the coil was the issue but it worked. I say that because when I took the carb off, and removed the bowl, I believe the float pin was stuck, but as I was messing around with the carb it fell out. So when I reinstalled it was moving freely. Anyhow, now just to get it out on the water to make sure she's back to normal. Thanks all.
 

cchildr84

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Re: 1984 Mariner 9.9C - Ignition Coil Spark Test

Well, everything went off with out a hitch this weekend. Took the boat out, motor started right up and ran like a champ. Top speed with just me, my dog, and fishing gear is 18-19mph on a smooth day.
 
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