RE: Webra engine service, WHO????
Kman,
...Need more info!
The current P5 Webra is very unlike the older Speed version.
I believe 14x12 to 16x8 is the recommended prop size for the [link=http://www.webra-austria.at/motor.php?search=1067&folder=AERO&lang=EN]P5[/link].
The older Speed engines would run with a 14x6 to 14x7 prop.