I also have spent countless hours trying to diagnose a very weak spark on a full crank Victa 160 engine.
It would only spark intermittently with a clean and perfectly dry spark plug with the gap reduced to 2 thou. Even then, it would only spark if it was rotated rapidly with an electric drill.
The coil and module all worked when swapped over to a replacement Victa 160 engine that Norm kindly rebuilt for me so I could get the mower back to the customer.
The engine does have a bent crankshaft on the flywheel side, which I think must be the problem, as the very weak spark when rotated at high speed indicates there is a not enough magnetic induction to allow the coil to produce a spark at the proper voltage.
I have got an oscilloscope reading of the coil output that I'll locate and post.
At the moment, I've had to put it aside due to many other jobs that still require attention, but I hope to try at some stage straightening the crank and fitting another flywheel to see if that fixes the weak spark.
