How to test Tecumseh Coil?

SeaKaye12

Lieutenant Junior Grade
Joined
Jul 3, 2005
Messages
1,107
I just acquired a 5HP Sears Tecumseh/Eska with the magneto ignition (it's a 1970 model

Spark initially was weak sometimes/non existent other times. I replaced the condensor. The points looked new...but I cleaned then a bit. The coil certainly looks OK.....but I need to check that now somehow.

Do coils typically fail? I've never had to replace a coil yet.....I initially doubted that the coil would be bad.....but I guess I might have been wrong.

Can someone walk me through the procedure to test the coil?

Thanks for reading, Chuck
 

SeaKaye12

Lieutenant Junior Grade
Joined
Jul 3, 2005
Messages
1,107
Re: How to test Tecumseh Coil?

To further clarify...(and to hopefully stir up a response... :)

I still have no spark after cleaning the points and replacing the condensor.

I suppose that by the process of elimination I should replace the coil...but I would like to learn something here...and that would be:

how to test the coil.

Visually it looks fine...and the connecting wires are good. How to test it???

Thanks for reading, Chuck
 

CATransplant

Admiral
Joined
Feb 26, 2005
Messages
6,319
Re: How to test Tecumseh Coil?

The shop manual says to check it by substituting a known good coil. I wish I could help more, but I don't know of a good way to test it.
 

fucawi

Banned
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May 18, 2011
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1,039
Re: How to test Tecumseh Coil?

you need to check the primary and secondary resistance ..expect very low ohms on the primary 0.3-1 ohm and a few thousand on the secondary ..the main point is you should have continuity.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: How to test Tecumseh Coil?

You said you have weak/no spark. How wide a spark gap are you trying to get out of that thing? 1/8" and you are doing good. Other motors wouldn't even run on such puny spark, but those do.
 

fucawi

Banned
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May 18, 2011
Messages
1,039
Re: How to test Tecumseh Coil?

you should be able to get a 1/4 in spark in air if its going to be any good at full cylinder pressure but you may not get that ..the colour and look of the spark is not relavent ..if it jumps the gap its good ...as output is low at low rpm you may have to pull the gap down to 15-20 thou on the plug
 
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