I believe the HRM215 models had the 140 GXV engines in them, so adjustment process must be similar to the HRC 216 160 GXV line.
Loosen the nut on the governor arm pinch bolt and move the governor arm rearward, as far as it will go, to the full throttle position.
With the governor arm held rearward, use pliers to rotate the governor arm shaft clockwise as far as it will go, and tighten the nut on the governor arm pinch bolt.
Start the engine and allow the engine to warm up.
Use a tachometer to check RPM's, with the throttle lever in the FAST position and the blade engaged.
I *think* the maximum RPM is 3,100.
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