Appears that Briggs did use a different than I used to seeing.

Okay the governor spring is PN 698726. If you can make out the color it is painted it should be Pink.
[Linked Image from ereplacementparts.com]

The designed top No-load Rpm is 2850 +/- 100 rpm.

To increase the rpm if needed bend the tab toward the throttle linkage while checking the speed with tach.
[Linked Image from i.imgur.com]