NOTE: I'm updating this thread and getting the broken pictures working again. Standby.
This thread details my diagnosis and repair of a cracked clutch plate and the damage it caused. The pieces got munched by the primary gear between the crankshaft and clutch basket. It produced a sound similar to the recording in this thread:
GARGOYLES in my 6!!
What Happened?:
I was starting gradually from a stop while on a STEEP incline. The bike was loaded up with me, my wife and empty Givi hardbags (approx 300 lbs). I heard a loud cracking while easing the clutch and throttling up. After the cracking sound I didn't hear or feel anything else unusual. So I gently continued on my way. About 1 mile later the engine suddenly developed the noise in the video linked above. Limped 1 more mile back home keeping it under 20 mph and riding as gently as possible. Bike performed ok, just made a racket of a noise. The engine makes a constant loud clacking noise which follows RPM not wheel speed. See the video below for a noise that sounds identical to mine (just after 3m:20s):
YouTube
My diagnosis so far:
Cam chain did not jump a tooth. I used a stethoscope around the engine and narrowed the noise down to the clutch area. Opened the clutch and found it was cracked. The friction plate closest to the transmission was cracked into multiple pieces. The pieces were pretty big and were still held in the clutch basket except for one small section of the ring that was missing. Dropped the oil pan and found small debris from the clutch plate. I visually inspected the gears on the crankshaft and clutch basket. They appear to have aluminum fused into them from the clutch plate. Yamaha used cast aluminum for the friction plates which is softer than the crank and clutch materials.
So what next?:
I believe the noise is gear interference caused by the clutch plate material fused in the primary gears on the crankshaft and clutch basket. This would have happened when the clutch piece ran through the gears. I tried removing the material by scraping but it was not possible for me to restore the gears. The tolerances are quite small. I pulled the engine and am currently in the process of replacing the crankshaft and clutch basket.
Important Replies:
Diagnosis Part 1 (clutch debris in oil pan)
Diagnosis Part 2 (removing clutch basket)
Diagnosis Part 3 (examining primary crank gears)
Repair Part 1 (crankcase split, new crank installed)
Repair Part 2 (crankcase mated)
Repair Part 3 (generator & clutch installed)
This thread details my diagnosis and repair of a cracked clutch plate and the damage it caused. The pieces got munched by the primary gear between the crankshaft and clutch basket. It produced a sound similar to the recording in this thread:
GARGOYLES in my 6!!
What Happened?:
I was starting gradually from a stop while on a STEEP incline. The bike was loaded up with me, my wife and empty Givi hardbags (approx 300 lbs). I heard a loud cracking while easing the clutch and throttling up. After the cracking sound I didn't hear or feel anything else unusual. So I gently continued on my way. About 1 mile later the engine suddenly developed the noise in the video linked above. Limped 1 more mile back home keeping it under 20 mph and riding as gently as possible. Bike performed ok, just made a racket of a noise. The engine makes a constant loud clacking noise which follows RPM not wheel speed. See the video below for a noise that sounds identical to mine (just after 3m:20s):
YouTube
My diagnosis so far:
Cam chain did not jump a tooth. I used a stethoscope around the engine and narrowed the noise down to the clutch area. Opened the clutch and found it was cracked. The friction plate closest to the transmission was cracked into multiple pieces. The pieces were pretty big and were still held in the clutch basket except for one small section of the ring that was missing. Dropped the oil pan and found small debris from the clutch plate. I visually inspected the gears on the crankshaft and clutch basket. They appear to have aluminum fused into them from the clutch plate. Yamaha used cast aluminum for the friction plates which is softer than the crank and clutch materials.
So what next?:
I believe the noise is gear interference caused by the clutch plate material fused in the primary gears on the crankshaft and clutch basket. This would have happened when the clutch piece ran through the gears. I tried removing the material by scraping but it was not possible for me to restore the gears. The tolerances are quite small. I pulled the engine and am currently in the process of replacing the crankshaft and clutch basket.
Important Replies:
Diagnosis Part 1 (clutch debris in oil pan)
Diagnosis Part 2 (removing clutch basket)
Diagnosis Part 3 (examining primary crank gears)
Repair Part 1 (crankcase split, new crank installed)
Repair Part 2 (crankcase mated)
Repair Part 3 (generator & clutch installed)
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