Make sure the kill wire isn't chafed and grounding out.

There is a small wire coming off the coil that goes to a little "junction block" There is a wire coming off of that block that goes somewhere. Is that the kill wire? If so, where does it go? Sorry for all the questions but I know very little about this.
I've got the coil off and the edges where it goes to the flywheel is laminated and one side has some slight separations in the laminations????

That's the kill wire.
It goes to the key switch (and probably one or more safety switches, depending on the application).

That wire is grounded with the key OFF (or safety switch "activated") to kill spark.

Disconnect that wire and then see if you get spark.
That's pretty much a GOOD/BAD test of the coil.

It might also be helpful if you tell us what this engine is on. Possibly a schematic is available.

First off I would like to thank everyone for the replies.
This engine is on an old Montgomery Wards lawn tractor that I bought new back in the early 90's. It is only used now several times a year to knock down weeds in an area that is pretty rough. This old mower has a lot of "band-aids" on it but it still serves the purpose. However, I don't want to put a lot of money in it. For the last year or two it would not start after it got hot but now it won't start at all. There is no spark to the plugs so I thought it was the coil. The part# I have for the coil is 394891. Is this correct? Where is a good place to get a new coil? Are the aftermarket one's any good or should I buy Briggs?

394891 will get you the entire Magnetron group, including 394988 armature (coil proper) and the 394970 trigger coil assembly.
I would stick with Briggs myself, but for my money I would certainly disconnect that kill wire from its connector and then spin the engine for a spark check before parting with that much cash.

Well, that last post got away from me before I was finished with it.
Depending on the Type Number of your engine and when your engine was built (code number) you may not even have a trigger coil. If you don't have a trigger coil then you don't have to worry about that and it appears that Briggs part number 394891 has been changed (I looked at a newer IPL) so that number now only gets you the armature (coil proper).
Sorry for any confusion I may have created.
Perhaps the separate trigger coil is no longer needed at all with an upgraded new armature.

Model 422707 1510
Type 01
Code 89092512
Trigger coil / armature?????

OK, engine built Sept 25, 1989. Type 1510-01
This engine DOES NOT feature a trigger coil and you only have to order the Magnetron armature, Briggs part # 394891.
Sorry I confused things but I first looked at the older IPL (for Types 0010 to 0210) and that's where the trigger coil was part of the picture.
I presume that the trigger coil is no longer necessary on any of the engines and can be removed if you are installing the upgraded Magnetron armature.

Per your question there is a way to test the coil. There are specified resistances for the primary side and for the secondary side of the coil. If the resistances are not meet the coil has failed.

Unfortunately I do not have those resistances as it has been thirty years since I checked one.

One good indication the coil has failed is, if there is either a short in the coil. no resistance; or a break in an internal wire, infinite resistance. You can also check for a short between each terminal and the coil ground, or case. As I remember the resistance was very low so could be seen as no resistances.

knuttle,
Are you saying to take an ohm meter and check from each plug wire back to ground and if it is good, there should be no reading? I'm trying to find a used coil but have not had much luck. I really hate to put a lot of money in the old mower as it is only used now and then to knock down weeds in some rough areas.

Since your engine is from the late 1980's and is fitted with a Magnetron coil, you can't test it by measuring coil resistance. The electronics and connections to the windings are all encapsulated in plastic. I understand that only a Graham or Mercotronic tester will work. But have no first hand knowledge of them. Usually a coil substitution is the best way to troubleshoot a Magnetron. Works well if you have a "goodie box" with a lot of take offs. However if you don't another coil, you'll spend about $40 or so for a new one.

My suggestion would be to reattach the coil and gap properly. Do not connect the kill wire. It should be a push-on connector (or maybe flying lead). Then remove both sparkplugs. Using either a test plug, or a sparkplug opened to .060 see if the spark will jump the plug. You need to gournd the plug to the engine while someone else cranks the engine for you. Try on both spark plug leads. If you get spark to both leads, you have a kill switch or interlock problem. If no spark at this point, you've got a bad coil.

Yes. I used to do a lot of my own work on my cars, but as I said previously that was a long time ago. I always found the information in Chiltons. You may find something on coil testing in Chilton's Small Engine Manual (It may be a similar name)

I did a quick Google and found these sites, if you take more time and do it more thoroughly you may be able to find something specific to your coil.

http://www.clarks-garage.com/shop-manual/ign-04.htm
http://autorepair.about.com/od/troubleshooting/ss/coil-test-ohm.htm

This is from the first site.

Perform an ignition coil resistance check as confirmation of the coil's condition.

Check the ignition coil primary coil resistance by connecting an ohmmeter between the positive (Black wire) and negative (Green wire) terminals on the coil. The resistance should be 0.4 to 0.6 ohms.
Check the ignition coil secondary coil resistance by connecting an ohmmeter between the coil output terminal and the ignition coil negative terminal. The resistance should be 5000 to 7200 ohms.

From the book.

{{gwi:325192}}

Kind of off subject. But I have have brought old ones back to life with a battery. I know someone will call BS but sometimes it works! I don't understand what happened and should know the answer since I'm an electrician.

My Dad showed me this trick, it worked a lot of times for him and also for me. Not every time, but about 60% of the time. But only if you had some resistance on the coil.

Put jumper cables on a 12 volt battery, hook the negative side to the disconnected "kill" wire. Spin the motor, you may need help with a pull start. Ground the spark plug wire. Touch the positive side to the motor for a few seconds, only while it is spinning.

Then check for spark.

Thanks everyone for the replies. It was a bad coil. I bought a new one & it runs great. $60 for the Briggs coil. More than I wanted to put in the old mower but I hear the after market one's are hit or miss, so........................