Kubota M4030SU engine under stress

[VenningG]

'91 M4030SU engine sounds like it's running under stress (load) of some type. Xmission and Xfer case in neutral, PTO disengaged. When I shift the hydraulic output to secondary (nothing connected), engine idles smooth again. Shifting back to primary (drawbars) engine is stressed and after an hour runs hot.

 

[art]

Your out of adjustment and it should be in your owners manual.