Did you try raking them with the tweezers? Raking tends to work better than pinching ime. When the coils are hot enough, the raking separates and shifts the wraps ever so slightly and creates more surface area to oxidize by marring it. Whether by separating the offending stretches or oxidizing them more, it tends to do the trick. You can see the wraps pop loose a little and then boom, it just works.
That's either a short or a connection problem. Be careful not to snap the wires, but try re-positioning the coils slightly while they're hot and fully tightened down. If worst comes to worst, you may have to back out a connection, choke up on the lead, and bring it back down to fix it. The idea here is to try and change the tension on the wire going into the post without damaging it. No matter how tight you have the screws down, the wire in there will always move when the coil does. Sometimes all it needs is a little tension shift to catch the sweet spot in there.
Sometimes it can actually be a connection issue with the coil that seems to be firing evenly. Sometimes what I think happens is that the coil with the better connection ends up stealing an uneven amount of current from the other... ...just little patches of extra current here and there. The coil with hot spots may indeed be fine and it's the other one that needs tweaking.
Or on the flipside, you could tighten down the wild coil until it's almost at the breaking point so it matches the connectivity of the weaker one. It's all about what you think will work best for making sure that they're making an even connection.
One thing is for certain, one of those coils is taking more current than the other. There's only so many points to attack the problem from. Keep playing with the connections, pulsing, scraping, etc... ...it can take some trial and error. Somethings gotta give, but hopefully it won't be one of your leads!
I hate it when that shit happens. Some atties of mine are on my shit list for consistently doing this. Can't tell you how many times I've sat down fidgeting with a set of duals for 15 minutes or more only to wind up snapping a lead in the process of snooping out the cause.
