Man I bought it from told me it would do this. He did not know why and said might be a bump in road that triggered it. He carried a 7/16 wrench just for this little thing.

Your going along fine---then all the sudden engine goes to idle. Throttle still open. To fix you remove the 4 bolts from round plate where the throttle shaft comes out of govener, pull plate out, set throttle in cab to idle, replace round plate and your back in business. ?????????? Comments welcome. LB

Sounds like the ratchet mechanism that holds the throttle position is worn out. Fairly common problem on well used machines as the ratchet/paul teeth wear and the holding springs get weak.
It is possible to rotate the outer ring (less dowl pins) to a less worn position but that may not solve the problem.
Last time I bought the ring and pauls from Cat they were extremely pricey and I may have got the last set.
Best bet is probably to look for a less worn used replacement.

If I understand you correctly, the throttle lever is not moving when the engine speed drops to idle. Am I correct?

If this is the case, the internal governor control shaft is becoming disengaged from the throttle ratchet assembly. Maybe too much end play in one part or other?

Jack

All throttle rods, handles, etc, all stay in the original position. All outside connections are tight. How would an endplay problem be solved? I think the ratchets are fine and make a nice click and everthing stays put. LB

Leaky, you must have a problem with the shaft as if the control arm (throttle) has not moved yet the engine slows down, it shouldn't be in the ratchet pawls. All those pawls do is hold the throttle arm in whatever postion it is set. It sounds like the entire pawl mechanism is changing position on the shaft. I don't know how to explain myself but there is a mating part that fits on the shaft that connects to the hub where the throttle linkage is attached. Check that shaft.

Maybe someone has a picture of a governor exploded view.

If it's not the locking mechanism then check the tang and groove coupling between the control shaft and the governor. Could be wear, excessive end play as Jack mentioned or just plain busted.

I'll do more looking next time I remove the cover. I remember a set of pins that went in slots when I pulled off the cover. The slots were still in the advanced position. I removed cover, reached inside cab and closed the throttle handle, then with fingers rotated counterclockwise the part in govener with the rachets so the cover part would go back inplace. When I started the engine it would once again rev up as normal. I'll look it over again and I do thank you all so much for the help. LB

There's a couple bolts that hold the ratchet assembly onto the side of the governor housing, and another inside the ratchet assembly. If you take out those three and pull the whole ratchet mechanism off you can see the shaft inside and see if the tang/slot are in decent shape. Also use a depth gauge like a vernier caliper tang or such to see if the inside shaft reaches the ratchet shaft adaquately. This procedure is not a great tear-down and may give you a hint of what's wrong.

Hope this helps. If it doesn't, I'll go out in the shop and dig out a governor I have torn down at the moment and see just what bears onto what else regarding the end play limits. So tell us what you find.

Jack

Thanks LB