Okay Ian, I'll bite........ "Pimp My Plane"?

Anyhoo, glad you got the plane up last weekend. I've had engines with no trumpets behave in a similar manner. Do a slow roll and when it gets to right knife edge, it runs richer and burbles. Runs clean at all other attitudes. Tried all the usual stuff, (cover over the diaphragm holes, tube to inside the fuse, fooling with the needles, flying while standing on one foot, etc.) with limited success. Pull hair out, didn't help. Certainly makes rollers interesting. I'm thinking airflow inside the cowl is different in right knife, and that affects things. I might remove the cowl and see if it still happens.

Tim