Stihl, No Visible Spark at Plug when Grounded

[etbrown4]

Over the years, troubleshooting a saw that won't start, I occasionally will test the plug for spark. Most everyone who has tried it will tell you sometimes you can see a spark if you have a good shadow, and sometimes you can't.
So what's up when you can't see a spark, again when you have a good shadow, but you put the apparently non-working plug back in and she fires?
I've seen some spark testers, but never tried one. Guess That's next.

 

[KASH]

You have to make sure the plug plug is grounded .The outer shell of the plug has to be againest metal .
Kash

 

[HarleyT]

The newer coils produce a weak looking spark. Test in a dark room.

 

[Old2stroke]

Are you pulling it over fast enough when testing? Electronic modules have a minimum RPM that must be achieved before they will spark.

 

[lone wolf]

Check in the dark as mentioned or find a stupid helper to touch it ,ha! If it still don't spark dis connect the kill switch and try.

 

[Backstage]

Never saw the need for a spark tester, but if I understand, they just tell if the plug is getting current. The actual plug could be damaged, gunked, or misadjusted.

 

[cgeb]

Check in the dark as mentioned or find a stupid helper to touch it ,ha! If it still don't spark dis connect the kill switch and try.

Yes to this.. Have helper put spark plug on tongue..

 

[HarleyT]

Check in the dark as mentioned or find a stupid helper to touch it ,ha! If it still don't spark dis connect the kill switch and try.

Touch what??