'Whirring' off idle as accelerating....

[Wylie7]

Hi Everyone, my 650gt makes an annoying noise at initial acceleration then quickly reverts to what consider 'normal'..... Just had service and mentioned this but it's still there..... I find it hard to accept that this is correct..... Sounds belt/variant or related to me. Bike has done 4k miles. Thanks Dan


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[SteveADV]

I just noticed what sounds like the same thing and I also have a little more than 4k miles. It doesn't sound like a big deal and is probably something that needs to be tightened. I'm riding in cold winter weather and that contributes, no doubt. My BMW tech is pretty sharp, so once I get it in to them (could be awhile with the current Ohio weather), I'll report back on the cure.

 

[Wylie7]

Thanks Steve.


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[SteveADV]

So today I had my 6k work done and asked my tech to look into the noise we talked about. Of course, I could not duplicate the noise. He rode the bike but could not hear anything either. After a complete and thorough exam, and not finding anything, I have nothing to report. Sorry about that.

 

[Doraemon]

I would say first to isolate the sound, front, middle, back. dowes the sound like metal on metal, metal on plastic, fan wirring.
I have not heard this on mine, but when I think of Whirring, I think of the flan blades associated with the cooling fins of the variator. It could be sucking the filter in; belt related could be the spring is too tight and binding up the belt. I would ride it a while then have them check the belt for wear on the sides..... just a few items to think about.

For me, If I am sure the sound is coming from my belt area, I would remove the covers and run around the block when I know I would possibly hear it, maybe have someone listen and look down while riding.... or start off next to them while they watch it. finally I might put it up on the main stand with the covers off and rev it while watching or recording it. locking the lever for the front brake so it would locked up.

 

[bill steele]

Most bikes have there quirky sounds and as time goes on you find that it is just that a quirky sound.

 

[Oldscoot]

Most bikes have there quirky sounds and as time goes on you find that it is just that a quirky sound.

My bike has a whine on throttle-off deceleration that sounds like the distant siren of a police car or emergency vehicle. It's getting quieter, and I am also used to it, but in the beginning I kept looking in the mirror for a cop.

 

[Doraemon]

My bike has a whine on throttle-off deceleration that sounds like the distant siren of a police car or emergency vehicle. It's getting quieter, and I am also used to it, but in the beginning I kept looking in the mirror for a cop.

I seem to remember having that symptom on a motorcycle and it seemed to be more the tire and road surface, at least in my experience.

If the effect happens to me then I will investigate as my above post. ONe other item to think of for the noise on take off; load of the bike, the weight of you versus tech.... uphill tak offs or level/downhill. the loading may make a noise on heavy versus light loading. it would explain intermitent noise and weather the tech could hear it or not.

every time you hear the noise, think about location, loading, road. log it all down when you can and look at commonalities. this is your chance to be a detective.

 

[Oldscoot]

I seem to remember having that symptom on a motorcycle and it seemed to be more the tire and road surface, at least in my experience.

I know the tire sound to which you are referring. No, this is definitely coming from the engine as it perform compression braking. It keeps me within the speed limit.

 

[SteveADV]

Being as non-mechanical as I am, any sound deserves investigation. Thanks for your tips, Doraemon. Hopefully, it is nothing more than a quirky sound like Bill was saying.

 

[Wylie7]

Thanks for all the input guys.... I've had the same sound on a Vespa GTS300 and it was belt related, I'll probably take it to the dealer again and get them
To ride it .....


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[Doraemon]

I know the tire sound to which you are referring. No, this is definitely coming from the engine as it perform compression braking. It keeps me within the speed limit.

Does the noise stop when the clutch releases below 10-15mph? compared to the Burg with electronic cvt, the BMW has very little engine braking when the clutch releases. If it's on take off and slow down, is it in certian speeds? could be clutch slipping perriod, until the clutch and bell lock up; thats why I switched to the Dr. pulley locking clutch. the stock clutch I had showed signs that the shoes were not contacting 100%, more like 50% (at 4500 miles) may have to do with the wear and seating the clutch and bell togeather.

just a thought

 

[Wylie7]

It's only there fir a second or two max in initial acceleration... At no other point..... Thabjs


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[otbiker]

Gear whine as they are spur cut in design.

 

[Wylie7]

Well, took scoot back to CW in Dorchester on Thursday..... Fantastic people! They could hear the noise this time. Embarrassed to say I thought the belt/variator was in the rear drive casing..... Now I know better .... Anyhoo, slight ridge on front pulley and a slightly tired/corroded bearing. BMW requested photos for analysis prior to any replacement. Re packing the bearing deffo improved things...... Am awaiting the call to book in fir the solution. Still loving it though!!


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[Wylie7]

Parts ordered..... But what parts?? Time will tell..... Need it done soon as Isle of Man TT beckons....


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[helmetbox]

It's only there fir a second or two max in initial acceleration... At no other point..... Thabjs


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The sound is like the brakes grinding on the disc, or some like diesel vehicle having a faulty belt.

I think I know what you meant. My bike has that sound too. Will get then to check when I'm going for my 10k servicing.

 

[helmetbox]

Well, took scoot back to CW in Dorchester on Thursday..... Fantastic people! They could hear the noise this time. Embarrassed to say I thought the belt/variator was in the rear drive casing..... Now I know better .... Anyhoo, slight ridge on front pulley and a slightly tired/corroded bearing. BMW requested photos for analysis prior to any replacement. Re packing the bearing deffo improved things...... Am awaiting the call to book in fir the solution. Still loving it though!!


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Can you give me more details on where the sound is being generated? Or what should I get the mech to look at it?

 

[Wylie7]

It's as you accelerate slowly, the whirring is at the front pulley on the right side ( not final drive on the left) it's a dry bearing and also mine had a ridge to the inside of the pulley..... Re packing the bearing improved things short term. Cheers Dan


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[yellasei]

You are in the best of hands there with the guys from CW, they are the keenest i know for warranty jobs. Is there any chance of getting hold of those pics from them and posting them up??