1987-2004 Kawasaki Mojave KSF250 Service Manual, Page 113Get this manual
8-18 CRANKSHAFTTRANSMISSION Gear DogGear Dog Hole and Recess Damage -Visually inspect the gear dogs, gear dog holes andor recessesReplace any gears that have damaged or excessively worn dogs, dog holes, or recessesBall and Needle Bearing Wear -Check the ball bearingsoSince the ball bearings are made to extremely close tolerances, the wear must be judged by feel rather than measurementClean each bearing in high flash-point solvent, dry it (do not spin the bearing wh ile it is dry), and oil it with engine oiloSpin the bearing by hand to check its conditionIf the bearing is noisy, does not spin smoothly, or has any rough spots, replace it-Check the needle bearingsoThe rollers in needle bearing normally wear very little, and wear is difficult to measureInstead of measuring, inspect the bearing for abrasion, color change, or other damageIf there is any doubt as to the condition of needle bearing, replace it