RE: Norvel .061 inverted runs poorly
Darren,
If it was a CL plane the most likely cause of 'rich inverted' would be a tank mounted to low below the needle valve.
I'm thinkin' our engines do not know whether they are pulling a plane controlled with waves or controlled with wires.
So . . . I'd say raise the tank and see what that did. And I would run a test on the ground by just holding the plane upright and then flipping it inverted.