Throttle body rattle

[Spout]

I've recently experienced the dreaded surging that sometimes afflicts our twins. I'm pretty sure the cause was some duff petrol, and after a couple of refills 'flushing the system out' I'm only occassionally suffering a bit of hesitation (at low throttle openings).
Generally the bike ticks over nicely, pulls well and doesn't vibrate (too much!).
But I have noticed that just off idle both left and right throttle bodies rattle alarmingly (loud clicking/tapping) which then disappears as the revs rise. I've never noticed this before.
I'm guessing it's the butterfly valves against their stop, but have read on this board that their bearings can go.
Is it likely that both sides would fail together?
Could any remnants of the 'duff' petrol be causing this?
Any other ideas on what might cause this?

Thanks in advance, and Happy New Year

 

[themadprofessor]

I think you will find that if, whilst the engine is idling you "very gently" touch and stabilise the cable pulley between the air body and the engine, you will find the rattle on that particular throttle body goes away.

I am told that this is the throttle body spindle wearing; it is more common on the Right hand body than the left (but eventually they both get loose); and that although you friendly local BWM dealer will offer you a complete body at ££££££s, it IS possible to obtain the throttle spindle on its own from Bing who make all the parts I am told.

Somewhere I have a FAQ about this that I downloaded as my RT does it on the right hand side only. Eventually I shall get around to replacing it. As mine does NOT surge then I am leaving it alone for now.

If you want me to dig around and send you the doument please PM me with you real email address. I think the document is either a pdf or a web page that I saved

I hope this helps.

Chris

PS - Never heard of dodgy fuel doing this. It is just wear due to use.

You mean you did not realise you were just supposed to put in your garage and admire Sir!!

 

[finglonga]

Are you sure its not the injectors just doing their thing? They make a tapping noise.

 

[Big Lad]

This may help.
http://www.ukgser.com/forums/showthread.php?s=&threadid=20340&highlight=throttle+body

 

[BigBen]

The same problem

I have a 1100 GS with the same problem a loud rattle from the right throttle body and when you touch the cable pulley it stops, i think this is definitely butterfly shaft wear or what the shaft runs in because i can feel and hear play when the bike is still by giving the pulley a little wobble if THEMADPROFESSOR can tell me who Bing is ( i am new to this site) i will try to track down some replacement parts or even have some bushes made, i also get a small back fire when i shut down quickly i am thinking this mite be down to air getting in down the side of the shaft any help would be appreciated