l have a jeep with a bad ac compressor and they dont make bypass pully is for a 97 cherokee. can l just by a smaller belt and skip the compressor pully?

yes

They do make a pulley that would take the place of the compressor for the non A/C equiped vehicles, that also uses the same belt as the A/C equiped XJ. My 93 XJ has this. The factory part #s are:
Bracket: 5300 6551
Pulley: 5300 2903
Bushing: 3300 2201
Pulley Bolt: 6502 137

The Bracket attaches to the top of the main A/C bracket..
Call ur local Jeep dealer to get prices & verify the parts r the same for ur 97, but l dont believe they changed.

numbers from the 97 XJ parts list r as above with the exception of the pully bolt, which is an M10 thread so u might get that cheaper somewhere else. The mounting bolts r also listed but not the thread. If u need different length bolts you'd need to compare the threads.

53006551 BRACKET, Idler Pulley
53002903 PULLEY, Idler
33002201 BUSHING, Idler Pulley
6504239 SCREW AND WASHER, M10x1.5x40

mounting bolt.

53010309 SCREW, (NOT SERVICED)