Hi,

I was hoping someone could confirm for me what I believe to be a failure in the internal governor mechanism on a Briggs and Stratton Intek twin, 20 hp.

Mower: Greenfields E2000 MkII.

Engine details:
Family YBSXS 7242VF 274844
Model 406777
Type 000714YH

Basic question:

Should the governor shaft only have 15-20 degrees of movement when the arm is freed/removed? Does movement in excess of this mean the governor set up inside the motor has came apart/adrift/failed?


Details:

I had a carbie problem which was solved with a small O-ring replacement in the float bowl. I refitted all the linkages and springs (3) after much thought followed by some googling (which showed I had the 2 springs related to the governor arm- the governor spring and governed Idle spring, correctly fitted). There was one other spring that appeared to connect to the choke mechanism at one end and to the other a bracket secured by the bottom left hand side manifold bolt. This I am not sure of as there are no holes to which it could realistically connect (it's a fine spring), leading me to convince myself that the only possibility was to hook around the choke bracket that allows the cable movement (across the mower) to actuate the choke linkage (rod). I couldn't find reference to this spring readily. The carbie is a Nikki with one float bowl.

Upon restart the engine revved hard regardless of the throttle setting (I had connected it). Of course it only ran for a small number of seconds before I shut it down. Much thought and inspection led me to discover that the governor arm did not, unless manually turned anti clockwise, push up on the throttle linkage much, leaving it well short of the adjustment screw. If I started the unit manually holding up the throttle linkage, the motor ran as expected.

I felt that the third spring should be pulling back the arm such that the throttle linkage was up against the idle adjusting screw, but there are no indications as to this being possible.

Googling suggested the governor (internally) failed in these motors, and that checking the range of motion in the shaft (taking movement from the governor arm and passing into the engine) would indicate whether failed or not. I didn't remove the arm from the shaft, but as the carbie and bracket were easily removed, I was able to free the linkage allowing the arm and shaft a full range of motion (well, 90 degrees at least). The arm and shaft easily rotated the full range possible- close to 90 degrees.

If it is a governor failure, is it pure coincidence, or ???? I didn't put any pressure on the governor arm and did not slap it backwards and forwards etc etc.

To add to my woes, the starter motor plastic drive gear has become separated from the shaft after a failure of the securing clip/s. The replacement kits seem to be around $40 if I can get them, with a whole new starter motor not much more than $110 (or thereabouts). I'm led to believe that the starter is part 497595 (C clips distinguish these, I believe).

I am already thinking about taking the motor out and paying someone to fix the governor if that is the problem. I don't like the idea of having to remove the drive and cutter pulleys from the shaft (crank?). A quick look suggests this will have to happen before it comes out of the mower, but hopefully I'm wrong and someone can reassure me.

Hope it was right to start a new thread. Apologies for any etiquette I have overlooked.

Thanks in advance