On my 240Ds and 300CD I would like to test for an optimum setting with current diesel fuel.

Without my taking out the manual can someone tell me how to mark where my timing is now and how to rotate IP so as to modify the timing. Is an audible highest idle the best setting for normal use??

I have no instrumentation so is by ear ok?? Thank y'all out there for your splendid help and expertise.

One final note.....I have no emission concerns. None.

__________________
Dionysius