Kai Glaesner wrote:
reading the "no RPM drop..." thread gave rise to a question: what is the
benefit (if there is any) of the "dual magneto" (two magnetos in a single
housing) installation? Should these kind of installation be preferred, or
avoided (if there is a choice ;-)?


While the mechanical drive to a magento can fail, it's not a likely failure.
The main reason there are two magenetos is not so much that the magnetos
themselves fail often, but something in the entire ignition system connected
to that magneto fails. Since magneto's are pretty weak sparks, the usual
culprit is some fouling of the spark plug.