in sequence edit go to the particular note with selector. press open window > change d: to 240 for 1/16'th ti 480 for 1/8th and so on... u get the picture.
Hmmn in a old MPC 2000XL manual or on page 5 in the 4000 reference manual is has a list of all the MPC 4000 ticks right next to the notes.
For ticks all I need to know like Reveal said it that the main resolution on the MPC 4000 is 960 per quarter note. After that I do the math divide by 2 for the note going down from a quarter note or times two for the notes going up pass a quarter note. For the triplets you have to work out the math but its easy.