Spark Plug Heat Rating ???

Initially the question about the "R" has been raised. According to what I learnt this indicates the spark plug will not interfere with radio receivers. Of course that is not needed if your spark plug connector is already protected.

regards

Holger

You only need 3 dials to sync the carbs. Each carb "pair" shares their sync adjustment. You can use either of the two intake paths to attach the hoses to sync the carbs.