Loss of power under load

[50BobP50]

I have a John Deere 2640 that loses power under load. Any ideas?

 

[Dieseltech]

I have a John Deere 2640 that loses power under load. Any ideas?

What injection pump does engine have? If it's Stanadyne/Roosa pump the flex ring inside pump might be failing and pump needs repair when that happens. Confirm by loosening the two screw timing cover on the pump side, if engine runs OK WITH the fuel leak but acts up with cover tight it's confirmed injection pump needs repair. This is assuming fuel supply TO injection pump is OK.

 

[flying belgian]

I have a John Deere 2640 that loses power under load. Any ideas?

Fuel filter?