I recently acquired a 2010 Makita with a B&S 500 Series motor...Machine is in great condition, only problem is that I cannot get it to increase its speed.
The motor has no problems of revving when you manually move the butterfly
I assume that the more tension applied to the governor spring (via the throttle control on the handle) the more the throttle opens...All linkages and cables appear to be doing what they should, but regardless of how much tension I apply to the spring, the throttle only opens about 1/3 way..

The governor arm should do the rest, the spring is a balancing act to allow the motor to come back to idle but then allow the governor to increase the revs as needed when cutting

Kenny what is the model and type numbers? The governor spring looks to be the wrong one but need look the ipl to verify.

Hi.. numbers are...10T602 0140 B1
Ken

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.


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.