When mowing the grass (it is no lawn) my mower often crunches into old roots or buried rocks. The sudden impulse almost always disturbs the governor and the engine begins to race. Over many years I have been adjusting the engine speed while the engine is running by simply pushing the throttle to the required position against the governor control rod action. I have never been happy with this method and I decided to investigate what is really going on, with a view to restoring its proper function.
It is a mountfield lawn mower has a Briggs & Stratton engine. The lever arm which ultimately moves the throttle is attached to a narrow axle which comes out of the crank case - this axle must be part of the actual governor. The lever attachment to the axle is not "tight". It is easily possible to move the arm relative to the axle. Nevertheless the governor continues to work. Presumably there is enough friction in the attachment and the force required to move the throttle is tiny - even when the balance spring is operating? Is this a feature or a bug?
I would like to know how to set the governor/throttle connections from scratch which, presumably, involves a rigid connection between the governor axle and the lever arm. Does anyone know how this is done? (I am in the process of trying to get info' from the manufacturer but have had no reply to my e-mail of several days ago.) With the petrol tank and starter attached the connection is inaccessible so I guess a standard position is set and the engine taken up to running temperature. Subsequently adjustments can be made if necessary but hopefully they won't be because its such a tedious business removing the petrol tank.
The engine specification is Model: 123802 Type: 0216-01 Code: 92022058
TIA Frank