No spark after compression test?

[zenwriter]

Did a compression test on my Johnson 90HP 2-cycle year 2000 carbed engine. Compression was OK but after putting back the plugs the engine wouldn't start, Coughed a couple of times at first but now seems just to be dead, no spark. Is getting plenty of fuel, cranking fast, new plugs look good.

Any thoughts on a component that a compression test could kill? (I followed the OMC service manual instructions, which did not include instructions to ground the plug wires.). Reason I did the test was engine was losing power at WOT, wouldn't rev over 4,000 RPM.

 

[jakedaawg]

What were comp readings?

Were you checking spark with what method?

 

[zenwriter]

To be honest I'm not the best mechanic nor do I have the best tools: Got a compression tester from Auto Zone &it maxed out at 92 on all 4 cylinders -- think it was the guage rather than low compression: previously it was between 120 and 125 on all 4. Didn't see any spark in the light-type tester I have, but there was fuel in the water as I cranked it. Key issue is that it started right up before my test, making me think I might have killed an ignition component. I did change the ignition fuse with no effect.

 

[Bosunsmate]

So no spark on any? your kill/lanyard cord is still attached ok? Always ground although most people seem to say you can get away with it

 

[interalian]

I always do compression test with the key off and use a clip-on starter switch to turn the motor over using the solenoid terminals. This ensures there's no chance of spark, hence no need to ground the coil outputs.