Outboard won't start

[jt11791]

I have a Johnson 9.9hp 2-stroke outboard that I'd like to get running. It hasn't run in a few years and I don't know much history on it. It is clean and looks to be in very good condition, but there is no spark when I turn it over.



I bought some new spark plugs, but still no spark.

I checked the kill button and it seems operational, pull it out open circuit, let it in shorts to ground.
It's solid state ignition, so no points to check.
I don't know what other tests I can do, short of shotgun replacing parts.


Any ideas on how to proceed appreciated.

[Adelie]

Did you check the gap on the new plugs?

[a64pilot]

You can check the magneto wires resistance, that should confirm that it’s good, it also should of course generate power when you spin the motor.
I know of no test for what’s most likely the CDI box, once you confirm the magneto is good, they rarely go bad, I’m afraid you may just have to buy a box.
Even if there is two cylinders it’s most likely still one coil that too can be tested with a multimeter.
If you can find a book on the motor hopefully it will tell you how to test both.