1980 9.8 Ignition testing

[Strecker25]

Hi all, having some issues with a 1980 9.8 idling poorly/misfiring at lower RPM's/stalling

I need to get a spark plug tester to verify, but I get a very weak, intermittent spark on the one cylinder. It does not follow coils. With the plugs pulled and grounded if I pull the starter one plug has the noticable "spark crack" the other only sparks if I pull very hard and even then its intermittent

I have the flywheel off and was hoping to test whatever I can with my multimeter. I found the following chart, can someone give me a basic idea of which leads to test for the listed resistance? I know it might be my ignition module, but I don't want to replace it with a new one if it's just the stator.

http://www.outboardignition.com/page39.asp

I've removed and cleaned carb, new wires, new plugs, cleaned up grounds, etc.

Here is the pic of the motor

 

[Strecker25]

I tested the below leads (circled) and get about 850ohms. What I'm not sure of is where that lines up on the chart I linked above? I would think those leads would test the stator? So if that's the case I'm way below the 1600-1800, or do these leads test the "trigger"? In which case, I fall within the 750-1400

 

[Strecker25]

One more info post, here’s a video of it running. At the end you can hear what I believe to be a misfire and then it stalls.
https://youtu.be/mhXIWc_dBC4

 

[RCO]

You need to test spark with an open air spark tester. Grounding the plugs against the block doesn't really tell you the whole story. It should easily jump a 3/8" gap. I watched your video, it sounded more like a lean sneeze to me, but it is really hard to tell with the motor on muffs . You can get a better idea of how it actually performs by running in a barrel to at least get the proper back pressure.

 

[Strecker25]

Thanks, I’ll do the gap test before throwing any parts at it. Until you said it I’ve never considered how much the back pressure would affect these 2 strokes, obviously much different than the 4stroke cousins.

 

[Strecker25]

Lesson learned, once you guys mentioned lean sneeze I went back to the carb. I had cleaned it last year but didn’t replace gaskets and I don’t think I tore it completely down. This time I did, soaked everything, new gaskets all around. I also cleaned all the stator and ignition components, even the flywheel. It runs pretty damn good now. I need to put a laser tach on it so I can adjust idle down. The only concern is the mixture setting needed to idle without a sneeze, 4.5 turns out which seems like a lot. I also replaced the float and adjusted it. Anyways, here’s the idle now

https://youtu.be/Dk9CYOu4O-A