Testing Stihl Coil

[champagnecharly]

Hello,

 

I'm hoping somebody can assist.

 

I am testing a stihl fs80av coil with a multimeter and am unclear on the results.

 

From HT-Poles i get 10.6Kohms

from LT - Poles I have continuity with less than ohms resistance.

 

HEre is a pic of the LT> poles with the test being performed across the red line..

http://dropbox.com/s/zt9ls3ixb5tb68c/IMG_6038.JPg

 

 

Do these read as they should or is it a sign of faulty coil?

 

What gets me is the logic on the LT side.. my logic is why would you have a kill switch to create connection to ground if the wire was already permanently grounded?

 

 

Hope somebody can clear up my confusion. Thanks in advance..

[Garyjp]

I have never found a successful way of testing a coil other using a test plug. If it sparks its good, if it doesnt...its buggered! (and that includes very expensive coil testers)

Just make sure the ground wire is isolated to clear up any issues with the switch.

 

 

 

 

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[champagnecharly]

Hi, Thanks

 

 

I had hoped for some logic on it.. oh well. I'll take it its had it then as there was no spark...

 

All was ok until all of a sudden the recoil starter cracked and flew off. (screw holding it came loose) it carried on running for a short while then stalled.

 

I tried to get it started with a battery operated drill. Nothing.. I checked for a spark. Nothing. Changed the plug still nothing. Thats when I started testing coil.. it all seemed a little strange for all to fail around the same time.

 

Thanks again for your post..

[spudulike]

Hi, Thanks

 

 

I had hoped for some logic on it.. oh well. I'll take it its had it then as there was no spark...

 

All was ok until all of a sudden the recoil starter cracked and flew off. (screw holding it came loose) it carried on running for a short while then stalled.

 

I tried to get it started with a battery operated drill. Nothing.. I checked for a spark. Nothing. Changed the plug still nothing. Thats when I started testing coil.. it all seemed a little strange for all to fail around the same time.

 

Thanks again for your post..

 

The fact you can get a resistance reading from the HT cap to the coil body means the HT cable and cap are OK, refit the coil, use a bit of A4 printer paper to set the flywheel to coil gap by placing the paper between the coil and the flywheel magnets and loosen the coil bolts letting the coil be drawn to the magnets and then do the bolts up. This is a smaller gap than usual but stick with it.

 

Make sure the kill wire is disconnected from the coil and then test for spart by putting the spark plug in to the HT cap, earth it on the cylinder and pull the engine over fast and check for spark, if no spark is found then try a different plug. if you still don't get a spark then the coil is duff.

 

The blown coils I have had have sparked once when first pulled over and then nothing!

[champagnecharly]

Thanks. I'll asume it to be dead as it was not sparking at all and switch is disconected.

 

Thanks

[mikerecike]

Thanks. I'll asume it to be dead as it was not sparking at all and switch is disconected.

 

Thanks

 

 

were you turning it by drill or recoil? - I have had a coil give nothing with an electric drill turn over and be fine with a manual pull - I imagine they operate best / properly at certain speeds of rotation