Vibration and throttle balancing

[Alphason]

Does anyone know: is it worth investing in a throttle balancing kit? I'd like to reduce the vibration, especially at idle, but I understand that the 1200 uses stepper motors to balance the throttles. I've read the Adv Rider help guide but it seems to be redundant on the 12, due to the use of steppers and the lack of manual adjustment. As the more experienced will realise, I have no experience of this subject, so no worries about 'sucking eggs'

Thanks in advance.

 

[Mouse]

I think you won't be able to balance thr throttles at idle, due to the stepper motors. Some people have speculated about unplugging them, but to my knowledge no one has tried that.

The steppers only work at idle though, so you can still balance on a partially open throttle, I found this improves things a bit.

But if the 1200 is like other GSs, people say making sure the valve clearances are right is more important.

 

[GrinningGSer]

to my knowledge no one has tried that.



I have,...........sort of, following a note from Clive

I maintained the electrical connections, so as not to cause any possible computer fault codes.

Just unbolted motors, plugged hole with modified plastic wine cork and left steppers dangling, but connected. Do not let any debris fall into the large hole.

Then balanced with home made manometer, as described elsewhere on this site.

Easy peasy, although stepper plunger rods can shoot out with their springs, but easily re seated.

The only issue is that I am not really convinced that doing this(albeit very easy and removes all the debate re stepper motors), makes the slightest difference to balancing smoothness.

I think that next time, I will just balance at 4000rpm, as Mouse posted earlier and forget all about the steppers.

I think that correct valve clearances (and I havent tackled this as yet) is a much bigger issue than worrying about the stepper motors, but perhaps someone techy will correct me ?

 

[Alphason]

Thanks for the input.

Am I right in thinking that the adjustment is made on the throttle cables but there is no manual adjustment on the throttle body butterflies? Or am I missing something?

 

[Emoto]

Thanks for the input.

Am I right in thinking that the adjustment is made on the throttle cables but there is no manual adjustment on the throttle body butterflies? Or am I missing something?

You are correct. If you follow the method that most of us seem to, which is to check and fix the synch somehwere above idle so that the steppers are mostly out of the loop (4k rpm works for me, but others go just above idle), you will probably only need to use the right-hand adjusters (right-hand when astride the bike) to synch them up.

 

[Alphason]

Thanks Emoto.

Having read loads of threads full of good info from mouse, wraithrider etc etc I've come to the conclusion that the best bet is to set the throttles up at around 4,000 with no load then use a twinmax to check under load conditions. This way the steppers are definately not operating against attempts to set up the TBs.

This way it's possible to get the balance much closer to perfect than the BMW spec of 15mbar.

If anyone's interested the links I found most useful:

http://advwisdom.hogranch.com/Wisdom/TBS4Dv1.0.pdf
http://www.advrider.com/forums/showthread.php?p=753066
http://www.ukgser.com/forums/showthread.php?s=&threadid=41565&highlight=throttle+balancing
http://advwisdom.hogranch.com/Wisdom/OilheadMaintenance.pdf