# Briggs & Stratton over revving



## rfcomm2k (Aug 1, 2015)

Have a B&S 21HP 2 cylinder motor model 407777. Was out mowing today and at a point had to back up, which automatically kills the mower deck. The engine started revving up very high, so I throttled down. Even with throttle at the lowest setting the motor was running faster than it normally did at full throttle.
Took cowling off and checked governor mechanism for debris, rust, etc. It was clean and moved with no trouble.
I had a helper restart motor while I monitored the governor. The internal rod from the crankcase moved with no restriction, and the carb linkage also moved. But the linkage did not move enough to throttle down the motor. I could force it to throttle down by moving the linkage with a stick, but that is not the answer.
Nothing appears damaged/bent, so I am puzzled.

Any suggestions?


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