Kitch

Please check this out.

(apologies for the cross post, but I need your help)

Presented for your delictation today is a mystery...

One full of cunning, intrigue and twists...

I have a mystery noise. I'm hoping somebody can tell me what it might be so I can look at making it go away.

So, the symptoms:

The noise sounds like a "slappy" noise, almost like an exhaust that's blowing from the headers. The noise matches the exhaust pulses and changes them from "put put put" to "twhap thwap thwap" (how's that for technical Smile )

It only occurs at idle speed and is intermittent. Sometimes it doesn't do it, sometimes it does. It also makes little difference whether its just started or been running a while.

What we know:

The bike has all fluids, oil, petrol, coolant etc.

The clutch feels fine at the lever.

There is no noticeable loss of power anywhere.

The CCT's are 3000 miles old with uprated springs and were fitted professionally.

It has 20k miles and was fully serviced at 16k

There is nothing I can see that is hanging off or leaking anywhere.



So, thoughts? Ideas? (UK site replies indicate its probably not the CCT)

Thanks

With motion pictures! Note how the noise is loudest on the left side near where the CCT is and also how it disappears with the tiniest amount of throttle.

http://www.youtube.com/watch?v=_M0uz-HG6jw

see here for the UK site thread:

http://www.vtr1000.org/phpBB2/viewtopic.php?t=9676

Thanks so much

cliby

have the carbs been balanced (recently? ever?)? It sounds more idle, carb slide related to me. Easy to check and would smooth out the idle - worth trying. Taking off the tank, airbox and hooking up an auxillary fuel or the stock tank relocated would allow you to pinpoint it further. but I'd start be checking if the carbs are synch'd

Kitch

It was fully dyno tuned recently.

Hawkrider

Man, that REALLY sounds like a cam chain. It seems louder on the left side, or maybe that was just the video, but if it truly is then I'd say it's the front cylinder. Try this: Pull the center bolt out of both cam chain tensioners. Use a small flat blade screwdriver and turn the CCT counter-clockwise. If it moves or jumps then the CCT is bad. If it barely moves and is tight then the problem is elsewhere. Don't forget to replace the center bolt.

Kitch

Thanks muchly Greg, I was hoping it was gonna be that.

I did check the rear one, which was tight, but didnt strip down to get at the front one.

Mechanic guy is looking at it now.

Pray for me I dont need a new engine.

I'll update exactly what it is for reference if anyone else gets this noise in the future.