T&T: Adjusting Engine Stop Solenoid Perkins 6.3544 (NA)

[Bob/Myrna Siegel]

Occasionally depressing engine-stop button fails to stop engine. It slows but
resumes running when button released.  Idle speed is 600 RPM as always.
"stop" solenoid on engine has a threaded rod with 2 nuts-one adjusts kill
speed and one locks the other nut.  What is the procedure for adjusting this
"kill" switch? Which way is the nut adjusted? Can do it by trial and error but
would prefer directions from listees experienced in making this adjustment.
Bob Siegel Annapolis