Best way to test an Ignition Coil ?

[FergFan]

Replacing my 12v Ignition coil on my Ferguson TO30 Z129...I've just installed my 2nd 12v ignition coil and I'm still not getting a spark out of distributor side of the plug wire. I've tested the ground on the coil and I've got nearly 12 volts(11. sumt'n) going into the coil..Whats the proper way to see if I'm getting spark out of this coil, other than holding the end of the coil plug wire up to a bare area of metal on the tractor.....plug wire is a bit short, only been able to hold plug wire from coil up to a bare spot of metal on the starter or up to the bolt on the side of the starter.

Should I be able to see a spark out of the coil ignition plug wire on the distributor side by doing this?

 

[ThomasH]

The simplest way of doing it is to plug the spark plug into the end of the wire and lay the end of the plug on the metal of the engine somewhere. You can observe the consistency of the spark as well as the intensity. Make sure you don't do it in bright sunlight though, or you won't see the spark.

 

[Jerry/MT]

Take an old plug, gap it to 1/4" to 5/16" and put that into a spark plug boot and hold it to a good ground ( some guys braze a sp ring clip to it so that can clamp it on a bolt, etc)and crank the engine over with ignition system on. In atmospheric conditions you'll see a FAT, BLUISH WHITE SPARK,the color of lightning when you crank the engine over IF YOUR PRIMARY IGNITION CIRCUIT IS UP TO SNUFF! You can also pull the center wire from the distributor cap, hold it near a good ground and crank the engine with the ignition on.

 

[FergFan]

which ignition coil is comparable to the Delco remy 293 R-B that I'm replacing?

 

[Jerry/MT]

6V system or 12v system? The correct 12v coil, used without a resisitor is NAPA IC-14SB or its equivalnet with ~3.2 ohms primary resistance.

Any 6V coil will work with a 6V or 12V system but the 6V coil used on the a 12V system requires a resisitor in series with the coil to limit the primary current to 4 amps maximum.

 

[FergFan]

Widened the point gap and adjusted the position of the rotor cap a wee bit and she is running like a champ now...Thank you all for the help