I am going to fit Accent Electronic ignition to my 400 I have been running one on my Kettle for 3 years without a hiccup my question is when I contacted Uwe at Accent he asked if my advancer cam was 13mm or 15 mm, I know there were 2 different types used could some clarify where it is I measure I would assume it would be the bore of the actual cam from memory it is shaped like a top hat and can be removed by taking off the bolt and opening the weights on the springs. Thanks in advance.