Hey guys, I have a PC78US-11 that has a nasty vibration at idle. It also spins down weird when you shut it off, almost like its still trying to run. Vibration clears up right around 1600RPM. Motor mounts look good, machine only has 1400 hrs on it. The only thing I can think of is that one of the injectors is going bad and its skipping at idle. Is there any common issues with these machines before I spring for a set of injectors?
You should probably do some troubleshooting before spending a bunch of money. Do you know which engine you have in the machine?
Check the hydraulic pump coupling.