Strange noise, 2005 S4R

[gharris333]

Hi all, need some advice,

After a week pounding round the Isle of Man for the TT, my bike's developed a new noise that I can't pinpoint and want to know if it sounds like a common problem and whether it needs looking into. As I can hear it over all the other usual engine rattling, it's got me worried.

The bike seems to be running fine but there's now a high pitch whiney rattle most prevalent at 3-4 thousand revs in certainly the first three gears, possibly the higher ones as well but not audible over the wind noise at higher speeds. Seems to only be heard when moving under load and goes away when in neutral or rolling with clutch disengaged. Most audible off the throttle when slowing down.

I initially put it down to exhaust cans but have tightened them up and its still doing it. The bike is missing the change from 3rd to 4th quite regularly and hitting a false neutral. I can't pinpoint where the sound is coming from exactly whilst riding but it's definitely below or behind me.

Any ideas???
Thanks, Graham

[rollo22]

Try the pressure plate bearing.

[Zimbo]

The S2R800 has an ATPC slipper clutch, and springs in the clutch are prone to breaking, could well be that. Do a search, a couple of members have had this happen, Gilps was one of them. Rich at Louigi Moto has sorted a couple out I think.

[gharris333]

Thanks for the replies. Will look at the clutch (this one is not a slipper item) but fitted new bearing, springs, 48 tooth basket and plates only 1200 miles ago. I'm doubtful it would be that but will have a look when I get a chance, certainly would make sense.

[Zimbo]

If your clutch is the conventional type it's unlikely to have an issue, they are pretty reliable.

[utopia]

In general engineering terms, I would tend to associate a whining noise with some problem with gears.
Of course there are many other possibilities though, but that is a fairly common source of such noises in any machinery.
Is there any possibility that the chain has been over-tensioned at some time, leading to output shaft bearing damage and consequent mis-meshing of the gears ?
Your comment that the noise is only present when the transmission is under load would tend to reinforce this suspicion.
It may well be something else less serious, but worth investigating anyway.

[gharris333]

The chain has certainly never been over tightened whilst I've owned it in the last year. If it was the output bearing, would I expect to see some engine oil escaping if the shaft is no longer rotating straight? I'm fairly sure its only missing gears (occasionally) from third to fourth indicating a worn selector. If the output shaft bearing had gone, would it not miss all the gears and also be audible if I'm just spinning the rear wheel by hand on the paddock stand?

Otherwise, I still haven't had a chance to look at it but another couple of rides have started to make me think the noise is speed related at 30-40 mph and not rev related (as it still does it rolling with the clutch disengaged at this speed and in any gear). Under and above this speed, I can't hear the noise. Think I will also have a look at the rear wheel axle bearings.

[Saint aka ML]

I miss gears in all gears at one time or another on this bike, on the other and on all others.

Some were worse then others having seemingly same clutch Monster 900 2nd to 1st, 996 was missing them mainly 3 to 4 or 4 to 3. SS mainly 4 and up.

Old 750 with wet clutch no issues. Current 695 with APTC **** clutch all the time and only up.

[gharris333]

Right, I've had a poke around the bike, both output shaft and rear wheel bearings seem fine with no play or noise. There is quite a lot of play and a small knock in the clutch release bearing so will get down the dealer and get a new one tomorrow - potentially good suggestion rollo22. Otherwise everything else seems solid, although there were a couple of tools banging together under the seat so that may also have been the issue. Only time will tell.

Thanks for all the suggestions so far....

[peter]

Had this on a sv 650. At a certain speed the front mudgaurd would twist and touch the tire.
Took me ages to work it out. Hope it's that simple for you.

[Dirty]

http://www.ukmonster.co.uk/monster/showthread.php?t=48144

[Mr Gazza]

:chuckle: I had forgotten all about that..:chuckle:

Just goes to prove that if you always expect the unexpected, nothing comes as a suprise..:rolleyes: