2013 Triumph Thunderbird

AT 1ST VALVE CLEARANCE INSPECTION, IT WAS DISCOVERED THAT THE RIGHT-SIDE EXHAUST DECOMPRESSION MECHANISM BROKE OFF OF THE CAMSHAFT AND SHATTERED, LEAVING METAL PIECES LOOSE UNDER THE CAM COVER WHERE THEY COULD POTENTIALLY INTERFERE WITH INTAKE OR EXHAUST VALVE OPERATION. NOT ALL PIECES ARE ACCOUNTED FOR. IT IS UNKNOWN WHEN THIS DAMAGE OCCURRED. THE MOTORCYCLE WAS SHOWING NO SIGNS OF MALFUNCTION. AN INTERNET SEARCH TURNED UP AT LEAST 7 SIMILAR INCIDENTS OF THE SAME PART, SAME SIDE ON THIS MAKE AND MODEL MOTORCYCLE, DIFFERENT YEARS.

NIOSE FROM REAR DRIVE HUB AND DRIVE BELT ;FEELING LIKE REAR TIRE IS LOOSE BUT ITS BEEN CHECKED. WEARING REAR TIRES OUT FAST 2000MILES A TIRE. WHEN COMING OUT OF TURN ILL GET A WIGGLE FEELS LIKE SOMETHING LOOSE.ITS BEEN DOING THIS EVER SENCE NEW

MOTORCYCLE HAS DEFECTIVELY DESIGNED CARBON FIBER BELT DRIVE SYSTEM. BELT CAN EASILY BE INCORRECTLY ADJUSTED WHICH CAN CAUSE THE BELT EDGE TO BE WORN AWAY, CAUSING BELT TO SNAP AT HIGH SPEED. BASIC PROBLEMS INCLUDE AN INADEQUATE ADJUSTING MECHANISM AND A CUSTOM BLENDED COATING ON THE DRIVE PULLEY THAT CAUSES THE BELT TO MAKE CHIRPING NOISES AND EVENTUALLY WEAR THE BELT AT AN UNREASONABLE SPEED IF IMPROPERLY ADJUSTED. FACTORY SPECS STATE THAT THE DRIVE BELT SHOULD RUN AGAINST THE OUTER RIM OF THE REAR DRIVE PULLEY RATHER THAN IN THE CENTER. NO OTHER BELT DRIVE SYSTEM IS ADJUSTED THIS WAY AND THAT WOULD BE REGARDED AS AN INCORRECTLY ADJUSTED BELT BY ANY OTHER BELT DRIVE MANUFACTURER. TRIUMPH HAS NOT MADE A BELT DRIVE SYSTEM SINCE THE 1920'S AND HAS NO EXPERIENCE IN THIS AREA. GATES RUBBER COMPANY DESIGNED THE BELT DRIVE SYSTEM AND THE COATING. THE REQUIREMENTS WERE THAT THE BELT DRIVE SYSTEM LAST THE LIVE OF THE GATES GT CARBON FIBER BELT (150,000 MILES). AS AN ASIDE, MOST BELT DRIVE SYSTEMS USED BY HARLEY DAVIDSON (THE ONLY COMPANY TO USE BELTS ON MOTORCYCLES SUCCESSFULLY THUS FAR) HAVE REAR DRIVE PULLEYS THAT LAST ABOUT 50,000 MILES. HARLEY DAVIDSON RECOMMENDS THAT THE BELT AND PULLEYS BE REPLACED TOGETHER AT 50,000 MILE INTERVALS. THE CORRECT FORMULA WAS TURNED DOWN BY TRIUMPH BECAUSE THE COATING PROCESS PRODUCED A BYPRODUCT CALLED HEXAVALENT CHROMIUM WHICH IS HEAVILY REGULATED BY THE EPA. TRIUMPH DEMANDED ANOTHER COATING. GATES DELIVERED IT BUT ADVISED AGAINST USING IT. TRIU

WHILE DRIVING DOWN LONG STEADY HILLS WITH CLOSED OR PARTIAL THROTTLE, THE ENGINE BACKFIRES, STALLS, AND WOULD NO LONGER RESPOND TO THE THROTTLE. IN TWO CASES, THE ENGINE WOULD RESTART AFTER TURNING THE IGNITION OFF AND BACK ON WHILE STILL MOVING. IN ANOTHER INSTANCE, REPEATED ATTEMPTS HAD TO BE MADE TO GET THE ENGINE RESTARTED, AFTER COASTING TO A STOP ON THE SIDE OF THE ROAD. *TR