1992-1998 Kawasaki PWC Jet Ski Service Repair Manual., Page 83Get this manual
FUEL AND OIL
SPECIAL WORDS ADJUSTING SCREWS The low and high speed mixture screws must NOT be removed unless damage the tapered end is suspected and the screws are to be replacedUnder normal service these two screws should remain undisturbedEach Keihin carburetor is individually adjusted at the factory using flow meterAfter the adjustment is completed, limiter cap is installed over the head of the screw prevent accidental tamperingUnder normal service these two screws should remain undisturbedCRITICAL WORDS Perform Steps 16 and 17, ONLY if the high speed or low speed mixture cannot adjusted properlyALSO, per form the steps only if replacement screws have been obtained and on handFailure adjust the low speed or high speed mixture would suggest the tapered end of one but not necessarily both of the screws has become damagedIn almost all cases, "damage" is caused by the screw being threaded too tightly and the tapered end of the needle becoming "grooved", because passed through the orif Once the needle is c'grooved", proper mixture cannot be obtained