9. DRIVE AND DRIVEN PULLEYS MXU 250 9 DRIVE AND DRIVEN PULLEYS SERVICE INFORMATION.................................................................... 9-2 TROUBLESHOOTING........................................................................... 9-2 LEFT CRANKCASE COVER ................................................................ 9-3 DRIVE PULLEY/DRIVEN PULLEY ....................................................
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9. DRIVE AND DRIVEN PULLEYS MXU 250 SERVICE INFORMATION GENERAL INSTRUCTIONS • The drive pulley, clutch and driven pulley can be serviced with the engine installed in the frame. • Avoid getting grease and oil on the drive belt and pulley faces. Remove any oil or grease from them to minimize the slipping of drive belt and drive pulley. Unit: mm (in) SPECIFICATIONS Item Movable drive face bushing I.D. Drive face collar O.D. Drive belt width Clutch lining thickness Clutch outer I.D.
9. DRIVE AND DRIVEN PULLEYS MXU 250 Bolts LEFT CRANKCASE COVER REMOVAL Remove the five bolts. Remove the recoil starter cover. Recoil Starter Cover Gasket Remove the dowel pins and gasket. Dowel Pins Disconnect drive belt air inlet and outlet hose from left crankcase cover (see page 6-5). Remove the left crankcase cover bolts and left crankcase cover. Remove the gasket and dowel pins.
9. DRIVE AND DRIVEN PULLEYS INSPECTION Inspect the bearing for allow play in the left crankcase cover or the bearing turns roughly → Replace. MXU 250 Bearing Gasket INSTALLATION Install the dowel pins and new gasket. Reverse the “LEFT CRANKCASE COVER REMOVAL” procedures. Install the left crankcase cover and tighten the bolts. Connect the drive belt air inlet and outlet hose and tighten band screws. Install the recoil starter cover and outlet hose cover.
9. DRIVE AND DRIVEN PULLEYS MXU 250 Remove the left crankcase cover. (Refer to the “LEFT CRANKCASE COVER REMOVAL” section in the chapter 9) Remove the drive pulley. (Refer to the “DRIVE PULLEY REMOVAL” section in the chapter 9) Nut Hold the clutch outer with the universal holder and remove the clutch outer nut. Special Universal Holder E017 Universal Holder Clutch Outer Remove the collar and clutch outer. Collar Clutch/Driven Pulley Remove the clutch/driven pulley and drive belt.
9. DRIVE AND DRIVEN PULLEYS Remove the movable drive face assembly and drive pulley collar. MXU 250 Drive Face Drive Pulley Collar Ramp Plate DISASSEMBLY Remove the ramp plate. Roller Remove the six weight rollers.
9. DRIVE AND DRIVEN PULLEYS INSPECTION Check each weight roller for wear or damage. Measure each weight roller O.D. Service Limit (replace if below): 22.8 mm (0.912 in) Measure the movable drive face bushing I.D. Service Limit (replace if over): 27.06 mm (1.0824 in) ASSEMBLY Install the weight rollers into the movable drive face. Install the ramp plate. Check the drive pulley collar for wear or damage. Measure the O.D. of the drive pulley collar sliding surface. Service Limit (replace if below): 26.
. DRIVE AND DRIVEN PULLEYS MXU 250 DRIVE BELT INSPECTION Check the drive belt for cracks, separation or abnormal or excessive wear. Measure the drive belt width. Service Limit (replace if below): 22 mm (0.88 in) ＊ Use specified genuine parts for replacement. CLUTCH OUTER INSPECTION Inspect the clutch outer for wear or damage. Measure the clutch outer I.D. Service Limit (replace if over): 153.5 mm (6.
9. DRIVE AND DRIVEN PULLEYS MXU 250 Loosen the clutch spring compressor and disassemble the clutch/driven pulley assembly. Remove the seal collar. Guide Roller Pin O-ring Pull out the guide roller pins and guide rollers. Remove the movable driven face from the driven face. Movable Driven Face Oil Seal Remove the oil seal from the movable driven face.
9. DRIVE AND DRIVEN PULLEYS MXU 250 Measure the clutch lining thickness. Service Limit (replace if below): 0.5 mm (0.02 in) INSPECTION Measure the driven face spring free length. Service Limit (replace if below): 131 mm (5.24 in) Check the driven face for wear or damage. Measure the driven face O.D. Service Limit (replace if below): 39.94 mm (1.
9. DRIVE AND DRIVEN PULLEYS MXU 250 Check the movable driven face for wear or damage. Measure the movable driven face I.D. Service Limit (replace if over): 40.06 mm (1.6024 in) Inner Bearing DRIVEN PULLEY FACE BEARING REPLACEMENT Drive the inner needle bearing out of the driven pulley face. ＊ Discard the removed bearing and replace with a new one. Remove the snap ring and drive the outer bearing out of the driven face. ＊ Discard the removed bearing and replace with a new one.
9. DRIVE AND DRIVEN PULLEYS MXU 250 Seat the snap ring in its groove. Apply grease to the driven face bore areas. ＊ Pack all bearing cavities with proper grease. Specified grease: Heat resistance 230°C Press a new needle bearing into the driven face. Special Oil Seal And Bearing Install E014 CLUTCH DISASSEMBLY Remove the circlips and retainer plate to disassemble the clutch. Circlip Retainer Plate ＊ Keep grease off the clutch linings.
9. DRIVE AND DRIVEN PULLEYS Install the damper rubbers on the drive plate pins. Install the clutch weights/shoes and clutch springs onto the drive plate. Install the retainer plate and secure with the circlips. Clean the driven pulley faces and remove any grease from them. Install the oil seal onto the moveable driven face. Apply grease to the Oil seal and install them onto the moveable driven face. Install the movable driven face onto the driven face.
9. DRIVE AND DRIVEN PULLEYS MXU 250 INSTALLATION Install the drive pulley face assembly and collar. Install the clutch/driven pulley and driven belt onto the drive shaft. ＊ Keep grease off the drive shaft. Install the clutch outer, collar. Hold the clutch outer with the flywheel holder. Install and tighten the clutch outer nut. Torque: 5.
9. DRIVE AND DRIVEN PULLEYS MXU 250 Install the drive pulley and ratchet. ＊ When installing the drive pulley face, compress it to let the drive belt move downward to the lowest position so that the drive pulley can be tightened. Make sure the ratchet into the splines on the crankshaft when the ratchet is installed. Do not get oil or grease on the drive belt or pulley faces. Splines Install and tighten the nut. Torque: 9.
