I think I know what you're talking about, kind of like a small ball bearing bouncing quickly in a tight space? Mine does it, but not all the time... not sure what it is, but it makes me want to take the valve cover off to look. Maybe it's an AIS issue or even fuel? I filled up at a different station yesterday and it was back with a vengeance on startup today.I thought that was a rattle issue? Mine sounds like a buzzing sound.
Yep, finally got mine replaced under warranty, i hear a slight rattle rattle right at 4k, but not anyhwere else. According to yamaha corporates "master engineer" the revised CCT is 1/4" longer.The CCT sound on bikes with failed CCTs happens at around 4-5k, then progressively gets worse, and affects all rev ranges.
This same sound is apparent during start up, at idle.
It sounds like a ball bearing bouncing around, or a screw driver resting on a running chain.
On failing CCTs the sound can come and go, but typically gets worse over time.
Procuring this part from Yamaha isn't easy, they will replace, under warranty only, there is no recall. Backorders are running about 2 months, as it is a very common problem. So common, they redesigned the CCT itself, as it was apparently a design flaw.
I'm starting to hear the buzzing sound on mine, and I certainly don't want ANY of that to happen. I'm taking it in for its first service this Saturday. Here's hoping I can get the problem resolved quickly. :sad5:What could happen? Chain skips a tooth, piston smacks a valve, engine locks up.
When it fails, you will hear the rattle, which means instead of tightening, it is loosening.
This can lead to a catastrophic failure.
It has already happened.