MG Car Repair: 1977 MGB ignition problem, ballast resistor, mgb gt

Question
Hi
I have a 1977 MGB that I just acquired. The previous owner just rebuilt the motor and added a Piranha electronic ignition and side-draft Weber carb. When I first start my car it misses and runs terrible at anything over idle speed, and continues even up to normal operating temperature sometimes for 20 miles of highway driving, After it stops missing it runs really well though. At first I thought it was a carburetor issue, but it still does it once it is warm. Also I touched the coil and it is too hot to be touched. I worked on an MGB-GT with a high performance ignition and I remembered it did about the same thing before we wired in the ballast resistor. My question to you is how and where would I wire in the resistor if my MGB needs one, because I no longer have access to all the manuals and wiring diagrams I used to. I've also got a wire that is grounded to my coil mount but isn't connected to anything and it looks to have either a diode or resister on it before it is grounded would that go to my hot side or my ground side of the coil?

Thanks in advance for any help and please apologize my scattered thoughts.
Ozzie

Answer
Hi Ozzie,
The coil should not get so hot that you can't touch it, which is an indication either the coil is bad, wrong coil or as you suspect needs a resistor. The ignition system dictates what coil or what resistor must be used so you need to check with either Piranha or one of their suppliers to find out what was suppose to be used with it. The only info I have is on the MG system.
You should not even look at the Weber carb yet, until you get the ignition corrected.
Howard