ORIGINAL: Flyboy Dave
There are two things that are essential for our engines to run correctly, and they are
tied to each other.....no matter what anyone says.
One....you must have proper fuel pressure for the engine to run properly in all positions.
Did you read this thread ? This engine has a large tank.
This response was to a different query.
e.g. the one I responded to.
BTW: If the engine is properly tuned it will run inverted w/o muffler pressure.
I found this out when my muffler came off in flight.