Set the operator’s control to half throttle. Remove the pin holding the yoke to the rockshaft arm. Squirt the threaded portion with WD-40. Push the throttle rod back to open the throttle fully and push the rockshaft arm back to simulate the governor at full speed. Loosen the lock nut and screw the yoke until the holes align, then lengthen the rod by one more turn of the yoke to compensate for wear. Install the pin and tighten up the lock nut. The manual details it very well. However, it doesn’t do a good job in describing what to do if there’s too much wear in the rockshaft.
The key and slot on the rockshaft extension and the keyway in the governor spring housing wear and creates play in the rockshaft. A few degrees of free play on the rockshaft translates into a lot of play at the throttle. The play in mine was enough to move the throttle butterfly from closed to full open. This delays the governor’s ability to change engine speed as load on the engine changes, making the tractor lose power as load increases and surge as load decreases.
Remove the yoke pin and unbolt the rockshaft bracket. The rockshaft extension shaft will slide out of the housing so don’t loose the key. Clean the grease and dirt and paint with acetone (nail polish remover), use Q-Tips until you don’t get any more dirt. Mix up about 1 inch of each tube of JB Weld, pack some in the key slot on the rockshaft and insert the key. Use clean tweezers, skin oils keeps it from adhering. Use the eraser end of a pencil to put a glob of JB Weld into the housing and the keyway. Then, insert the rockshaft and leave it alone for 24 hours. Mine is sitting outside in the dead of winter, so I suspect it will take longer – I’ll give it several days to cure.
I used some plastic wrap and aluminum foil around it to prevent dripping. I let the JB Weld cure for 48 hours in sub-freezing temperatures. The joint is rock solid now and the governor can be adjusted with confidence. Removing the play makes a huge difference in performance and smooth operation.
