I have learned quite a bit from this thread. First, installation errors are often the source of problems when installing a new BTH. They were for me as well as Minivin. Second, I learned that a lot of ignition theory is still replete with mistakes and misinformation. Third, it is brightness, not color, which is most helpful in assessing the condition of the magneto in the air test (when comparing true magnetos of like design). Fourth, the air test for electronic ignitions, like the new BTH, can only tell you if the ignition is functioning. The brightness of the spark has no apparent relationship to the condition of the ignition as it does when comparing two stock magnetos.
As to the interest in high performance ignitions on Vincents being "absurd to the extreme", there are a few of us who have been trying to relocate to this fantasy world for quite a few years. The stock magnetos, even the TT racing magnetos, have proved to be highly unreliable in the modern vintage racing environment. When Carleton Palmer was racing, he used magnetos built by Mr. Bell, Mr. Gearhart and one well-known British rebuilder. All failed. Some failed with surprising rapidity. Carleton had to switch to electronic to get some needed reliability. BSA Owner, who has helped my racing efforts selflessly, has seen these results at the racing venues and in his own workshop. Many, if not all of the top Manxes are running Interspan electronic ignitions, not because it is a fad, but because they produce lots of high energy sparks for long periods of time. In my own memory of Bonneville runs, I remember only one ignition failure, which was a stock KVFTT. Fortunately, it came after a record run. Most of the other Vincents are running new BTH's and I have never heard of any failures. So, I did not take any offense, but I do like working on going extremely fast.
David
