Whistling/Whiring Noise

Whatup guys, been a long time since I have posted anything on here.

I have only just started up my bike for the first time in about a year. Before I put her away in storage the bike was making a slight whistling noise at low RPM that really started to piss me off. Preformance of the motorcycle was not affected but the noise was quite noticeable at low RPM and it is even more noticable now. Preformance is still not affected though. Does anyone have any idea what this could mean, my biker mates tell me its just a yamaha thing, but the bike never used to make the noise so why should it start making it now? Its bugging the hell out of me.

It sounds like its comming directly from under the tank. All the airbox seals seem sweet to me, ive checked the camchain and that was all good. Even took the cover off and had a look at the cams and shims. They are all in spec too. New Spark plugs/oil/filter, still noise.

Should I completely rebuild the carbs and see if that helps? They need a clean anyway after being unused for a year. I got a funny feeling it could be the carbs or something around that area. Maybe even a clutch bearing?

Any help would be greatly appreciated.

Chur.

 

Thanks Dave,

I did have a funny feeling that it could be a carb boot seal ontop of the engine or maybe even a leaky exhaust gasket. I will try the garden hose trick tomorrow. I have tried it with a long screw driver before but got nothing. Seemed to be alot of noise coming out from the clutch cover though, thats what gave me the idea that it could be a bearing in there...

 

Replaced the Airbox seals and took her for a run tonight for the first time in ages. Whistling noise had pretty much disappeared.
Slight rattle comming from the EXUP, probably fix that this weekend