There is a screen for sync the 4000 up to other sequencers, but it doens't come up on my mpc. The sync menu doesn't come up at all, and I can't locate the screen to sinc it.
stop the sequencer from playing. move the cursor to the sync field in main mode and press the orange window key. Make your settings according to your situation and press the window key again or press F1 to close the window. Don't forget to turn on the sync as well.
Same thing in song mode.
If you use OS1.51t you can also acces the sync page in misc mode.
Cheers!