4020 throttle stuck wide open

[haytedder]

1967 4020 diesel synchro, hand and foot throttle. Grandson wanted to drive it and I told him to shut it off by pushing throttle up. Strong kid, 6'5 240! Might have pushed a bit too hard and handle goes a little more than it did. Tractor starts up wide open, push hand throttle to shut off right away. No change in fast RPMs moving lever. Took dash and shield off over fuel pump. Both hand and foot throttle appear operable at pump. Everything looks OK mechanically. Did we snap the throttle rod off in pump? Anyone experience this before? Appreciate any help to get him back in the seat.

 

[Dieseltech]

Might be time for injection pump repair too, that's how they act when the weight retainer pins shear off. I repaired four JD pumps last month for the same trouble. If the pump lever moves back and forth OK I'll bet the pump need repair.

 

[haytedder]

Thanks for the reply. Yes, throttle moves at pump. I'm afraid the 4020 will be down awhile.

 

[fdt860]

(quoted from post at 14:32:14 07/30/23)
1967 4020 diesel synchro, hand and foot throttle. Grandson wanted to drive it and I told him to shut it off by pushing throttle up. Strong kid, 6'5 240! Might have pushed a bit too hard and handle goes a little more than it did. Tractor starts up wide open, push hand throttle to shut off right away. No change in fast RPMs moving lever. Took dash and shield off over fuel pump. Both hand and foot throttle appear operable at pump. Everything looks OK mechanically. Did we snap the throttle rod off in pump? Anyone experience this before? Appreciate any help to get him back in the seat.

Remove the vertical panel that holds the key switch and check on the throttle mecanism. If I remember correctly, the throttle countershaft is only hold in place by a spring.