2004 Yamaha FZ6 Owner Complaints

Front drive shaft, chain sprocket ‘Nut/lock washer’ has came loose and fell off on the highway. Could have locked the chain around the wheel and cause a major crash, also could have severely damaged the engine casing. It damaged the rear swing arm and a piece piece near the stater. I replaced the nut & locking washer tab, exact replacement only To have the same issue just I didn’t allow it to spin off since I was aware of this happening. I replaced the second one with a different style but same locking washer tab same issue it comes loose within 8 to 10miles. The nut is torqued to spec as stated by Yamaha. Iv reached out to several places including Yamaha and cannot seem to find a solution. Iv joined motorcycle forums and read people with same issue I’m having and wow am I lucky one. But they have had replacement parts and labor performed because of a safety recall of the issue. Why can I not get this resolved I have no clue what els to do.!! Please help

NHTSA ID

11506635

Incident

Nov 21, 2022

YAMAHA 2004 FZ6 BIKE RUNS GOOD FOR A WHILE, AND ALL THE SUDDEN THE ENGINE LOSES 90 % OF ITS POWER, I HAVE TO TURN THE KEY OFF, THEN BACK ON TO REGAIN POWER WHILE IN TRAFFIC, ONE TIME THIS HAPPEN I GAVE IT TO MUCH GAS TO GET OUT OF TRAFFIC ,AND I FLIPPED THE BIKE OVER IN THE MIDDLE OF THE STREET. IT WAS MY LUCKY DAY NOBODY RAN OVER ME. LOOKING AT THIS WEB SITE , THERE IS A LOT OF OTHER FZ6 RIDERS WITH THE SAME PROBLEM, I HAVE ASKED 4 YAMAHA DEALERS IF ANYONE ELSE IS HAVING THIS PROBLEM AND THEY ALL SAID NO? WELL THEY SURE DO BY LOOKING ON THIS WEB,I HAVE THE EXACT SAME PROBLEMS AS THOUGH OTHERS ON THIS SITE, AND A FACTORY RECALL IS NEEDED! SOMEONE GOING TO DIE IF NOT ALREADY THAT WE KNOW OF BECAUSE OF THIS PROBLEM. *NM

NHTSA ID

10169691

Incident

Sep 10, 2006

Mileage

3,000 mi

MOTORCYCLE SHUTS OFF AFTER REDUCING THROTTLE DURING DECELERATION AND DURING SHIFTING. MANY RIDERS OF THE SAME MODEL MOTORCYCLE HAVE REPORTED THE SAME PROBLEM. THIS IS DANGEROUS BECAUSE THE BIKE IS W/O POWER AND SOMETIMES DURING DOWNSHIFTING THE REAR TIRE LOSES TRACTION AND CAUSES THE BIKE TO SLIDE SIDEWAYS. *NM

NHTSA ID

10161468

Incident

Jun 13, 2004

Mileage

300 mi

(1) NO UNUSUAL EVENTS. (2) THROTTLE POSITION SENSOR FAILED CAUSING POOR GAS MILEAGE, STALLS, AND HESITATION. (3) REPLACED TPS AT A COST OF $215. *NM

NHTSA ID

10159712

Incident

Jun 9, 2006

Mileage

8,000 mi

AT 9M MILES, MY 2004 YAMAHA FZ6 BEGAN TO EXHIBIT THE FOLLOWING: 1) AFTER APPROXIMATELY 30 MINUTES OF OPERATION, ERRATIC AND PROLONGED PERIODS OF ROUGH IDLE AT 500 RPMS INSTEAD OF THE NORMAL 1300 RPMS 2) MOTOR WOULD STALL DURING GEAR CHANGES, EVEN AT HIGHWAY SPEEDS 3) DURING THESE TIMES, THE SMELL OF GASOLINE WAS NOTICEABLE. CHANGING THE SPARK PLUGS SEEMED TO FIX THE PROBLEM TEMPORARILY, BUT THEY SOON REAPPEARED. AT 12M MILES, THE BIKE WAS TAKEN TO THE YAMAHA DEALER TO BE FIXED BUT THEY COULD FIND NOTHING WRONG WITH IT. I WENT NEXT TO AN INDEPENDENT MOTORCYCLE MECHANIC WHO ALSO COULD FIND NOTHING WRONG. HE SUGGESTED THAT IT WAS PROBABLY AN ELECTRICAL PROBLEM AND COULD BE EXPENSIVE TO FIX AND I SHOULD TAKE IT TO A DIFFERENT DEALER. HE ALSO QUESTIONED IF THE "CHECK-ENGINE" LIGHT HAD COME ON WHICH WOULD HAVE REGISTERED SPECIFIC TROUBLE CODES, BUT I TOLD HIM THAT THEY HAD NOT. AT 12800 MILES, WHILE PULLING ONTO THE ROADWAY, THE BIKE STALLED UNEXPECTEDLY IN A TURN AT LOW SPEED, LOCKED THE BACK TIRE AND WENT DOWN. I SUSTAINED MINOR INJURIES, AND THE BIKE LOST A MIRROR, FOOT PEG, FRONT FAIRING, AND GENERALLY GOT BUMMED UP. SINCE THEN, I HAVE FOUND NUMEROUS REPORTS OF "THROTTLE POSITIONING SENSOR" DEFECTS THAT HAVE CREATED SIMILAR PROBLEMS WITH THIS MAKE AND MODEL OF MOTORCYCLE. AND YET, THE DEALERS SEEM TO KNOW NOTHING ABOUT IT! INSTALLING A NEW TPS MAY OR MAY NOT FIX THE PROBLEM. BUT FOR NOW I'M STUCK WITH A BIKE THAT I CAN'T TRUST, HAS LITTLE RESALE OR TRADE-IN VALUE, AND PROBABLY ISN'T SAFE TO RIDE. AFTER READING THE NUMEROUS AND SIMILAR SOUNDING COMPLAINTS, THIS MAY WELL BE A MANUFACTURING DEFECT THAT SHOULD RESULT IN A RECALL. *NM

NHTSA ID

10157688

Incident

May 12, 2006

Mileage

12,800 mi

VEHICLE: 2004 YAMAHA FZ6 MOTORCYCLE, PURCHASE NEW 12/93. INTERMITTENTLY, THE ENGINE SURGES, CUTS OUT, LUGS, STALLS/QUITS AT VARYING TIMES AND SPEEDS/RIDING SITUATIONS. STOPPING THE BIKE, TURNING IGNITION OFF AND ON TEMPORARILY CORRECTS PROBLEM, BUT PROBLEM ALWAYS RECURS. DIFFERENT WEATHER TEMPERATURES AND FUEL GRADES HAVE NO POSITIVE EFFECT. BIKE MAY STALL AT AN INTERSECTION STOP, AT HIGHWAY SPEED, ACCELERATING OR DECELERATING, ON STRAIGHT OR CORNERS, WHICH CAN BE TERRIFYING--NOT TO MENTION POTENTIALLY FATAL. NOTE: DATE LISTED BELOW IS ONLY THE MOST RECENT--PROBLEM OCCURS ON ALMOST EVERY RIDE. *JB

NHTSA ID

10153851

Incident

Mar 16, 2006

Mileage

19,840 mi

THIS COMPLAINT IS IN REGARDS TO THE 2004 YAMAHA FZ6 THROTTLE POSITION SENSOR. AFTER THE MOTORCYCLE WARMS UP (APPROXIMATELY 50 MILES OF RIDING), IT WILL STALL OUT AND/OR SPUTTER WHEN THE CLUTCH IS ENGAGED AND/OR SHIFTED INTO NEUTRAL. LAST JULY IT STALLED OUT IN THE MIDDLE OF A RIGHT HAND TURN AROUND A RED LIGHT, RESULTING IN THE BACK TIRE LOOSING TRACTION AND CAUSING A CRASH. I WAS MINIMALLY INJURED, BUT THE BIKE SUFFERED SOME EXTERIOR DAMAGE. AFTER SOME RESEARCH I HAVE FOUND THAT THERE IS A PROBLEM WITH THE THROTTLE POSITION SENSOR. THIS PART WAS FIXED UNDER WARRANTY, BUT SEEMS TO BE AN ISSUE WITH MOST OWNERS OF THE 2004-05 FZ6.*JB

NHTSA ID

10153797

Incident

Jul 17, 2005

Mileage

8,000 mi

THE MOTORCYCLE HAD PROGRESSIVELY WORSE STALLING AT STOP-LIGHTS AND STOP SIGNS. AT TIMES THE MOTORCYCLE WOULD STUTTER AND STALL WHEN TRYING TO INITIATE THE THROTTLE FROM A STOP, AND AT OTHER TIMES THE MOTORCYCLE WOULD RANDOMLY INCREASE SPEED WHILE CRUISING ON THE HIGHWAY. THE THROTTLE BECAME QUITE VARIOUS TO THE POINT IT WAS NOT SAFE TO RIDE IN TRAFFIC DUE TO NOT KNOWING HOW THE MOTORCYCLE WOULD REACT TO DIFFERENT THROTTLE INPUTS. IN ORDER TO FIX THE PROBLEM THE THROTTLE POSITION SENSOR HAD TO BE REPLACED. *NM

NHTSA ID

10149681

Incident

Jan 10, 2006

Mileage

14,000 mi

MOTORCYCLE'S IDLE RPMS CHANGE ABRUPTLY, TO THE POINT OF STALLING WHEN AT SLOW SPEEDS. THIS ABRUPT CHANGE WAS THE SOURCE OF A REAR END COLLISION. THE BIKE HAD BEEN TAKEN IN PREVIOUSLY TO THE DEALERSHIP ON MULTIPLE OCCASIONS BUT NO CORRECTIVE MEASURES WHERE TAKEN, AS THE PROBLEM COULD NOT BE REPRODUCED. THE SYMPTOMS CORRELATE WITH THOSE OF OTHER FZ6 USERS AND HAS BEEN LINKED TO A FAULTY TPS. *NM

NHTSA ID

10147316

Incident

Oct 9, 2005

Mileage

4,834 mi

MOTORCYCLE RANDOMLY WILL NOT IDLE AND STALLS BETWEEN SHIFTS. HAS HAPPENED 5 OR 6 TIMES. DEALER SAYS DESCRIBED SYMPTOMS CANNOT NOT BE DIAGNOSED WITHOUT FAULT CODES. FAULT CODES ARE NOT STORED UNLESS CERTAIN "IDIOTIC LIGHTS" COME ON DURING FAILURE. *NM

NHTSA ID

10137517

Incident

Sep 16, 2005

Mileage

6,500 mi

BIKE IDLE DROPS (600-850 RPM) WHEN CLUTCH PULLED IN CAUSING VEHICLE TO STALL AT RED LIGHTS, EXITING DRIVEWAYS ETC... POOR FUEL MILEAGE AND ROUGH IDLE. UPON CYCLING THE IGNITION KEY OFF AND ON, SYMPTOM WILL TEMPORARILY RECTIFY ITSELF ONLY TO RETURN LATER. I AM FEARFUL OF A REAR-END IMPACT FROM ANOTHER VEHICLE AT INTERSECTIONS AS A RESULT OF THIS PROBLEM. IT SEEMS THAT THE "THROTTLE SENSOR ASSY" PART NO. 5FL-85885-05-00 IS THE MAJOR CULPRIT PER OTHER OWNERS EXPERIENCES WITH THIS VEHICLE AND SAME SYMPTOMS. *NM

NHTSA ID

10136569

Incident

Sep 8, 2005

Mileage

4,900 mi

'94 FZ6 - 5,000 MILES. THE BIKE HAD A HARD TIME STARTING. NOW IT CAN BE RUNNING AT A STEADY 3000-4500 RPM ON THE HIGHWAY AND START TO STUMBLE OR CUTOUT. I'VE HAD TO PULL OVER AND CUT IT OFF AND RESTART IT TO GET IT TO STOP. IT HAPPENS WHENEVER IT WANTS, NO WARNING OR REASON. IT STALLED ONCE WHILE I WAS ON THE WAY TO WORK AND I DROPPED THE BIKE BEFORE I COULD CATCH IT. I'VE HAD FRIENDS TELL ME THAT IT IS A TPS (THROTTLE POSITION SENSOR), BUT THE MOTORCYCLE IS OUT OF WARRANTY AND I DON'T HAVE THE MONEY TO TAKE IN TO BE CHECKED. THAT WOULD BE ALMOST $100 AND THEY MAY NOT FIND IT. *NM

NHTSA ID

10135675

Incident

Sep 3, 2005

TROTTLE CHUNKY/DELAYED/ERRATIC, MAKING MOTORCYCLE DIFFICULT TO CONTROL IN CORNERS. STALLS AT STOPS, A DANGEROUS SITUATION IN CITY TRAFFIC. DOES NOT IDLE, I NEED TO KEEP THE THROTTLE SLIGHTLY ROLLED ON. RUNS ROUGH, SMELLS OF GAS, SEEMS TO MISS. PROBLEMS STARTED WITH THROTTLE DELAY AT 7000 MILES, STALLING STARTED AT 7400 MILES. *JB

NHTSA ID

10135318

Incident

Sep 4, 2005

Mileage

7,400 mi

RIDING HOME FROM WORK ON A 2004 YAMAHA FZ6, WITH JUST OVER 5K MILES ON IT. THE BIKE BEGAN TO SURGE BY ITSELF AND WOULD EITHER GO TO A FULL OPEN THROTTLE (WITHOUT ANY USER INPUT) OR WOULD HOLD A CONSTANT RPM (REGARDLESS OF USER INPUT). THE FIRST SURGE WAS VERY VIOLENT (WHEELIE STYLE THROTTLE INPUT) AND NEARLY KICKED ME OFF THE BACK. LOST GRIP WITH MY THROTTLE HAND, BUT WAS ABLE TO GRAB CLUTCH AND AVOID AN ACCIDENT. VERY INCONSISTENT THROTTLE RESPONSE THE REST OF THE RIDE HOME (~4 MILES). SOUND FROM EXHAUST HAD ALSO DIES DOWN AND WAS VERY QUIET. UPON ARRIVAL AT HOME, I PARKED THE BIKE AND FELT THE EXHAUST AND IDLE - EVERYTHING WAS NORMAL. UPON THE SLIGHTEST THROTTLE INPUT ABOVE IDLE, THERE WOULD BE NO PRESSURE FROM THE TAIL PIPE AND THE AIR AROUND THE EXHAUST WOULD BECOME INSTANTLY SUPER HEATED. I HAD THE BIKE TOWED TO A REPAIR SHOP (DEL AMO MOTORSPORTS) TO HAVE IT LOOKED AT. THEY RAN DIAGNOSTICS AND FOUND NO ERRORS. HOW CAN THERE BE NO ERRORS WHEN THE BIKE DROVE AROUND WITH A MIND OF ITS OWN? THE BIKE IS STILL AT THE DEALER, WILL UPDATE THE REPORT LATER. HAVE HAD ALL SERVICE CHECKS, BIKE HAS BEEN DOING FINE, EXCEPT FOR A ROUGH IDLE, DIAGNOSED AS A TPS PROBLEM BY TEXAS YAMAHA SOUTH OUTSIDE OF HOUSTON, TX. THIS WAS DONE AROUND THE 700 AND AGAIN AROUND THE 1200 MILE MARK. PROBLEM (ASSOCIATED WITH TPS, AS DIAG. BY TYS) STOPPED AROUND 1400 MILES THEN SHOWED UP AROUND 4700 AND HAS BEEN DOING IT EVER SINCE. *NM

NHTSA ID

10134992

Incident

Aug 26, 2004

Mileage

5,615 mi

1. BIKE STARTED AND WARMED UP FINE. AFTER ABOUT AN HOUR OF RIDING BIKE WAS IDLING VERY LOW AT A STOP SIGN (800-900 RPM). POWER DELIVERY WAS CHOPPY FROM A STOP ALSO. AT THE NEXT STOP LIGHT THE BIKE STALLED, AND I NEEDED TO USE THE THROTTLE TO KEEP IT IDLING . I SHUT THE BIKE OFF AT SOME POINT, TURNED IT BACK ON AND THE BIKE WAS BACK TO NORMAL. AFTER ABOUT 10 MORE MINUTES OF RIDING THE BIKE STALLED AT ANOTHER STOP LIGHT. SINCE FIRST OCCURRENCE THIS PROBLEM HAS BEEN INTERMITTENT BUT USUALLY GOES AWAY IF THE BIKE IS SHUT OFF, THEN TURNED BACK ON. . *NM

NHTSA ID

10134693

Incident

Aug 29, 2005

ENGINE RPM'S WOULD "STUMBLE" INCREASINGLY MORE FREQUENT, STALL AT IDLE. THROTTLE POSITION SENSOR DEFECTIVE AND NOT READILY IDENTIFIED AS DEFECTIVE BY AUTHORIZED DEALERSHIP. POOR THROTTLE RESPONSE/STALLING LED TO POOR CONTROL AT HIGHWAY SPEEDS, EXITING RAMPS, HARD CORNERING WHERE NEED FOR IMMEDIATE THROTTLE RESPONSE WAS REQUIRED. TWO OF THESE UNITS HAVE FAILED ON MY MOTORCYCLE, A 2004 YAMAHA FZ6. *JB

NHTSA ID

10132668

Incident

Jul 19, 2004

Mileage

7,800 mi

BIKE STALLS WHEN CLUTCH IS PULLED IN. RPM'S DROP TO ZERO. WAS ALMOST RUN OVER BY TRAFFIC BEHIND ME WHEN ENGINE STALLS. INJURED MYSELF (FOOT/ANKLE) WHEN TRYING TO PUSH THE BIKE OFF THE ROAD (SO I WOULDN'T BE RUN OVER). I'VE BEEN TOLD BY MANY FZ6 RIDERS THAT MANY OF THE FZ6 BIKES HAVE DEFECTIVE THROTTLE POSITIONING SENSORS (TPS) AND THAT YAMAHA HAS NOT RECOGNIZED THE PROBLEM. I BELIEVE IT TO BE A VERY SERIOUS SAFETY ISSUE. SOONER OR LATER, SOMEONE IS GOING TO GET RUN OVER BECAUSE OF THIS DEFECTIVE SENSOR. *NM

NHTSA ID

10132562

Incident

Aug 8, 2005

Mileage

4,550 mi

I HAVE A 2004 YAMAHA FZ-6 AND I BELIEVE THE THROTTLE POSITION SENSOR IS BAD. THE BIKE STALLS AND RUNS VERY ERRATICALLY AT LOW RPMS. I HAD TO PULL TO THE SIDE OF THE ROAD AND TURN THE KILL SWITCH AND KEY OFF TO RESET THE SYSTEM AND THEN IT STARTED AGAIN. IF THIS WERE TO HAPPEN IN A HIGH TRAFFIC AREA THE BIKE COULD STALL AND CAUSE AN ACCIDENT. I HAVE DONE NOTHING TO REPAIR THIS PROBLEM YET, I AM WAITING TO SEE IF THERE IS A RECALL ON THIS PART. I KNOW THAT THIS IS A VERY COMMON PROBLEM WITH THIS MODEL MOTORCYCLE. *NM

NHTSA ID

10130716

Incident

Jul 31, 2005

Mileage

12,050 mi

I HAVE HAD ISSUES WITH MY YAMAHA FZ6. THE MANUAL ADVISES TO USE 87 OCTANE FUEL. I HAVE BEEN USING 87 UNTIL THE BIKE STARTED TO IDLE AT VERY VERY LOW INTERVALS. CAUSING LOSS OF POWER WHEN DRIVING, OR STOPPED. NORMAL IDLE IS 1320 RPM. IDLE WILL DROP BETWEEN 600-800 RPM WHEN STOPPED CAUSING THE BIKE TO DIE (EVERY TIME) OR WHILE DRIVING THE BIKE WILL IDLE FINE THEN THE RPM'S WILL DROP WAY DOWN , THEN BACK UP THEN DOWN THEN WAY BACK UP. I TOOK THE BIKE TO THE REPAIR SHOP AND THEY SAID THEY WOULD ADJUST THE BIKES IDLE. THIS FIXED THE PROBLEM FOR A MONTH AND THEN I BEGAN HAVING THE SAME PROBLEM AS BEFORE. IDLE DROPPING AFTER FILLING WITH 87 OCTANE. I DECIDED TO TRY OTHER FUELING STATIONS 87 OCTANE. STILL NO CHANGE. I DECIDED TO TRY 89 OCTANE. WITH 89 OCTANE, SMALL IMPROVEMENT, WITH THE SAME ISSUES. I THEN DECIDED BECAUSE OF THIS PROBLEM CAUSING ME TO HAVE 4 CLOSE ACCIDENT ENCOUNTERS TO GO AHEAD AND TRY 92 (PREMIUM GRADE OCTANE). THIS SEEMED TO FIX THE PROBLEM OF THE IDLE DROPPING WAY DOWN, HOWEVER, THE IDLE STAYS HIGHER NOW THAN THE NORMAL 1320 RPM. NOW AROUND THE 1400 RPM RANGE. THE BIKE STILL HAS A ISSUE WITH POWER CUTTING IN AND OUT WITH NO IDLE CHANGE. I'M REPORTING THIS PROBLEM BECAUSE I HAVE HAD 4 ALMOST CRITICAL ENCOUNTERS WITH OTHER VEHICLES BECAUSE OF THE LOSS OF IDLE/POWER WHILE EITHER BEING STOPPED OR DRIVING. I DECIDED TO POST THIS PROBLEM UP ON WWW.SPORTBIKES.NET. I FOUND THAT 5 OTHER FZ6 RIDERS HAD THE SAME PROBLEM AND THAT THEY TOO HAD CLOSE ENCOUNTERS WITH OTHER VEHICLES. JUST FYI I MADE THE POST ON 07/29/05 AND ALREADY ON 07/30/05 THERE HAVE BEEN 5 OTHERS WITH THE SAME BIKE, HAVING THE SAME ISSUE. THIS IS A GREAT AMOUNT. SOME HAVE TRACKED THIS PROBLEM DOWN TO THE TPS - THROTTLE POSITION SENSOR. THEY REPORTED AFTER HAVING THIS REPLACED THIS FIXED THE PROBLEM COMPLETELY. SENSE I HAD THIS PROBLEM WITHIN THE 6 MONTHS OF HAVING THE BIKE, AND DUE TO OTHERS HAVING THIS ISSUE, A RECALL ON THIS BIKE SHOULD BE ISSUED. *JB

NHTSA ID

10130660

Incident

Jul 30, 2005

Mileage

4,000 mi

IN SEPTEMBER OF 2004 AT APPROXIMATELY 5000 MILES, THE MOTORCYCLE BEGAN IDLING POORLY AND STALLING. HAD TO TURN OFF THE KEY AND THEN BACK ON BEFORE IT WOULD START AGAIN. YAMAHA REPLACED THE THROTTLE POSITION SENSOR AFTER BRINGING IT TO THEM TWICE WHICH CORRECTED THE PROBLEM. I HAVE ALMOST 13000 MILES ON IT NOW AND IT IS DOING THE SAME THING AGAIN. IT IS A SAFETY ISSUE BECAUSE IT IS DISTRACTING AND HINDERS MY ABILITY TO WATCH TRAFFIC AND FREQUENTLY STALLS AT TRAFFIC LIGHTS.

NHTSA ID

10129651

Incident

Jul 20, 2005

Mileage

5,000 mi

THE MOTORCYCLE STALLED REPEATEDLY IN HIGHWAY TRAFFIC.

NHTSA ID

10127497

Incident

Jul 1, 2005

Mileage

5,000 mi

ENGINE HESITATION, MISSING AT HIGHWAY SPEEDS, ENGINE SHUTS OFF WITH NO THROTTLE. THIS IS A KNOWN ISSUE WITH YAMAHA AS TPS FAILURE ON THE FZ6.

NHTSA ID

10125081

Incident

Jun 12, 2005

Mileage

11,300 mi

I WAS RETURNING HOME TO PLANO, TX FROM A WEEKEND TRIP TO COLORADO. I WAS ABOUT AN HOUR AWAY FROM HOME, WHEN I STARTED TO EXPERIENCE ENGINE HESITATION WHENEVER I RELEASED AND REAPPLIED THE THROTTLE. THE NEXT DAY, THE HESITATION WAS GONE, BUT I NOTICED THAT MY FUEL MILEAGE HAD GONE WAY DOWN (FORMERLY 42-45 MPG TO THE CURRENT 35 MPG). THE ENGINE IS ALSO RUNNING RICH, ENOUGH THAT I CAN SMELL UNBURNT FUEL IN THE EXHAUST. THE ENGINE ALSO HAS STARTED TO IDLE ERRATICALLY, FLUCTUATING IN RPMS.

NHTSA ID

10125026

Incident

Aug 24, 2004

Mileage

9,600 mi

THROTTLE "JUMPS" UNEXPECTEDLY DURING NORMAL OPERATIONS OF THE MOTORCYCLE. WHEN TRAVELING SPEED WILL DECREASE AND THE ENGINE WILL "SPUTTER", THEN THE ENGINE WILL JUMP BACK TO SPEED CAUSING A JOLT FORWARD. SYMPOTMS BEST DESCRIBED AND THE FUEL BEING CUT OFF THEN ON AGAIN.

NHTSA ID

10122558

Incident

Oct 28, 2004

Mileage

6,000 mi

2004 YAMAHA FZ6 5K+ MILES. WHEN CRUISING AND KEEPING THE ACCELERATOR CONSTANT, ONE EXPERIENCES SUDDEN CHANGES IN ENGINE-TO-TRANSMISSION POWER FEED: THE BIKE SUDDENLY STARTS TO ACCELERATE OR SLOW DOWN. ONE MUST COMPENSATE CONSTATNLY FOR THAT ERRATIC ENGINE BEHAVIOR, WHICH TAKES AWAY FROM PAYING ATTENTION TO THE ROAD. IF DOWNSHIFTING, UPSHIFTING OR CLUTCH DISENGAGEMENT IS PERFORMED DURING THE ENGINE FALTERING, THE RESULT IS A STALLED OUT ENGINE UNLESS SHIFTING IS PERFORMED VERY QUICKLY. STALLING OUT WHILE DOWNSHIFTING FOR A FULL STOP AT AN INTERSECTION GETS DICEY GIVEN THE AMOUNT OF OIL/WATER USUALLY FOUND AT STOP LINES AND THEIR APPROACHES. THIS PROBLEM TENDS TO APPEAR AFTER ABOUT 20-30 MINUTES OF ENGINE OPERATION AT ALL SPEEDS, TEMPERATURES OF ENGINE OPRATION. IT CLUTCH IS DISENGAGED, THE ENGINE IDELS DOWN TO 400-500 RMP (INSTEAD OF THE USUSAL 11-12K) AND INVARIABLY STALLS. STARTING THE BIKE RIGHT BACK DOES NOT ALLEVIATE THE SITUATION. THE ONLY REMEDY I WAS ABLE TO FIND WAS TO TURN THE IGNITION OF, TURN IT BACK ON (EVEN AFTER 2 SECONDS) AND START EH BIKE AGAIN. IDLING RMPS COME BACK TO NORMAL AND THE BIKE RIDES FINE AFTER THAT. TURNED BIKE INTO DEALERSHIP, REPORTING THE ABOVE SYMPTOMS ALONG WITH REPORTS OF THROTTLE POSITION SENSOR PROBLEMS REPORTED BY OTHER FZ6 RIDERS. DEALER COULD NOT REPLICATE THE PROBLEM AND SIMPLY REPLACED IOL/GAS FILTERS, AS WELL AS OIL. UPON RECEIVING THE BIKE BACK FROM THE DEALERSHIP, OF COURSE THE PROBLEM CAME BACK.

NHTSA ID

10121061

Incident

May 15, 2004

Mileage

5,000 mi