Motorcycle Repair: VW coil on my cb200, volkswagen beetle, voltage spike

Question
Hello, I am currently building a cafe style racer from a 1974 honda cb200. I saw one that had two car coils hooked up to the ignition and so I wanted to do the same because I thought it would run better. I bought two coils for a 68 Volkswagen beetle and hooked them up using the stock motorcycle condenser. (probably a mistake) It ran for a bit really good, but now it wont even start. I checked the timing and points gap, but still nothing. Then I changed the plugs again and it started right up, but after I shut it off, it wouln't start again. Someone said I should get the factory VW condenser that is rated for the coils and install it on my bike. Will that solve my problem? Also, I could see the points arcing across the gap when the engine was turning over. Thanks, Ben

Answer
Ben, I've not seen this modification before so I'll have to take a guess based on the physics.  The arcing you see is typically an indicator of a bad condenser. That engine had one coil for both cylinders.  By using two separate coils to do the same job,you are at least doubling the current and the voltage potential across the points as they are starting to open. The condenser is intended to absorb and store that voltage spike until the points close and it can discharge the energy stored in the condenser to ground.     

So, I think you've been given pretty good advice. Try getting a condenser with a higher rating or add another condenser and see if that doesn't eliminate the spark across the points.

Good luck
Rich