NHTSA Complaint #10000938 — 2000 KAWASAKI KLR650

THIS INVOLVES ENGINE PART #13168-1436 (LEVER, IDLER SHAFT) IN THE ADJUSTMENT MECHANISM OF THE ENGINE'S BALANCER TENSIONER SYSTEM. I HAVE REMOVED A FAILED LEVER, IDLER SHAFT FROM MY KLR650 ENGINE. I HAVE ALSO ASSISTED IN THE INSPECTION OF THIS PART IN OTHER KLR650 ENGINES AND HAVE FOUND OTHER INSTANCES OF FAILURE. IN MY EXPERIENCE, THIS COMPONENT HAS TWO MODES OF FAILURE: WELD SEPARATION, AND BREAKAGE OF THE TOROIDAL-SHAPED SECTION THAT MATES WITH #39115-1077 (SHAFT-IDLER). KAWASAKI CUSTOMER SERVICE HAS PLACED THE BLAME FOR THE FAILURE OF THIS COMPONENT ONTO THEIR CUSTOMERS FOR NOT HAVING PERFORMED THEIR ENGINE MAINTENANCE IN A TIMELY FASHION. ON THE CONTRARY, THE VERY ACT OF ADJUSTING THIS MECHANISM MAY PRECIPITATE COMPONENT FAILURE. THE PROPER ADJUSTMENT OF THIS MECHANISM INVOLVES THE LOOSENING AND RE-TIGHTENING OF ADJUSTER BOLT #92150-1394 (BOLT,6X16). THE LOOSENING OF THIS BOLT ANY FURTHER THAN 2 TURNS OR SO PERMITS THE LEVER, IDLER SHAFT TO PARTIALLY/COMPLETELY DISENGAGE SHAFT-IDLER AND SLIDE DOWNWARD AND OUT OF ALIGNMENT WITH THE MATING SURFACES OF SHAFT-IDLER. THE RE-TIGHTENING OF BOLT,6X16 CAUSES THE LEVER, IDLER SHAFT TO BECOME WEDGED OR BREAK IF THE RECOMMENDED TORQUE IS APPLIED TO THIS BOLT. FAILURE NOT IN CONNECTION WITH THE ADJUSTMENT PROCEDURE HAS ALSO BEEN OBSERVED. LEVER, IDLER SHAFT MATES ONTO SHAFT-IDLER WITH A VERY LOOSE FIT. THE NORMAL CRANKSHAFT SPEED VARIATIONS PRESENT IN A SINGLE CYLINDER ENGINE ARE LIKELY TO PROMOTE COUNTERBALANCER DRIVE CHAIN WHIP WHICH IN TURN CAUSES A CYCLIC ROTATION OF SHAFT-IDLER. THIS MOVEMENT IS ARRESTED BY LEVER, IDLER SHAFT WHICH EVENTUALLY FAILS FROM THE RESULTING FATIGUE. A BETTER FIT OF LEVER, IDLER SHAFT ONTO SHAFT-IDLER WOULD SUPPRESS THIS DAMAGING ROTATION. I BELIEVE THAT THESE ISSUES PRESENT SAFETY HAZARDS DUE TO THE STRONG POSSIBILITY OF ONE OR MORE OF THESE FAILED COMPONENTS BECOMING SHRAPNEL AND CAUSING THE BREAKAGE OR DERAILMENT OF THE COUNTERBALANCER AND/OR CAMSHAFT DRIVE CHAINS.