Actually that OHV single manual doesn't cover the 09P but is a good starting point. Briggs hasn't released a service manual for that is specific for it. We have to use our training and experience to figure things on our own.
The following APSIs and DSB covers this engine.
APSI 85Page 7 of the APSI 85 shows the exact setup for the governor spring and the dynamic adjustment info.
APSI 103Additional Info.
DSB 1060New carburetor module info.
