Clunky gear change.

[Mac One]

This is just an observation I've made that may be of interest or help to someone.

I've got a 2011 twin cam GSA, and when I manage to get the throttle bodies balanced properly it pulls like a train with no popping on the overrun, ( I've removed the exhaust flap)
and gear changes are as slick as a slick thing.

When the throttle bodies are out of balance, the acceleration's poor ( unless you wring it's neck) it's noisier, lots of popping on the overrun, and the gear changes are really clunky
up and down through the box, to the point i thought there was something wrong with the clutch.

So it's worth taking a bit of time to get the TB sync right. So now, is it Twinmax, Carbtune, Digisync, Harmonizer, GS911 to lock the idle actuators, disconnect the idle actuators, bike overheating.

Cheers.

 

[Beemerman59]

Harmoniser + GS911 + floor fan from Screwfix

 

[Steptoe]

This is just an observation I've made that may be of interest or help to someone.

I've got a 2011 twin cam GSA, and when I manage to get the throttle bodies balanced properly it pulls like a train with no popping on the overrun, ( I've removed the exhaust flap)
and gear changes are as slick as a slick thing.

When the throttle bodies are out of balance, the acceleration's poor ( unless you wring it's neck) it's noisier, lots of popping on the overrun, and the gear changes are really clunky
up and down through the box, to the point i thought there was something wrong with the clutch.

So it's worth taking a bit of time to get the TB sync right. So now, is it Twinmax, Carbtune, Digisync, Harmonizer, GS911 to lock the idle actuators, disconnect the idle actuators, bike overheating.

Cheers.

Someone ought to tell bmw about this revelation, then they could add it as part of a bikes service schedule.....

 

[Mac One]

Fair enough, I suppose I was asking for some flak, but the gear change thing was not something I thought would be affected by out of sync TBs and if you do your own servicing it might be something you don't give much attention to.

Anyway that's all I have to say about that. Cheers

 

[mpgscott]

I have an akrapovic can with the baffle out and the flapper removed, i have the TB balanced and my gear change is lovely. 34K miles covered and it does give a nice pop and bang when you come off the throttle which i love hearing and it also pulls like a train. So not sure if the pops and bangs are necessarily something to go on to mean its balanced?? I spent a fair bit of time making sure my TB were balanced up as well however after reading this post i might re-check the balancing. However its maybe down to the can on mine are you running a standard can on yours Mac?

 

[Mac One]

I have an akrapovic can with the baffle out and the flapper removed, i have the TB balanced and my gear change is lovely. 34K miles covered and it does give a nice pop and bang when you come off the throttle which i love hearing and it also pulls like a train. So not sure if the pops and bangs are necessarily something to go on to mean its balanced?? I spent a fair bit of time making sure my TB were balanced up as well however after reading this post i might re-check the balancing. However its maybe down to the can on mine are you running a standard can on yours Mac?

Yes, standard can and headers, If your bike's running well don't go adjusting it. My post was just a suggestion of something to consider if your bike wasn't running well and had these symptoms.

It'll end up running like a tractor and you'll blame me.

 

[mpgscott]

YIf your bike's running well don't go adjusting it.

It'll end up running like a tractor and you'll blame me.

Brilliant, not at all its good to get advice for sure. I will leave mine for now..

Cheers

 

[dirty_t]

This is just an observation I've made that may be of interest or help to someone.

I've got a 2011 twin cam GSA, and when I manage to get the throttle bodies balanced properly it pulls like a train with no popping on the overrun, ( I've removed the exhaust flap)
and gear changes are as slick as a slick thing.

When the throttle bodies are out of balance, the acceleration's poor ( unless you wring it's neck) it's noisier, lots of popping on the overrun, and the gear changes are really clunky
up and down through the box, to the point i thought there was something wrong with the clutch.

So it's worth taking a bit of time to get the TB sync right. So now, is it Twinmax, Carbtune, Digisync, Harmonizer, GS911 to lock the idle actuators, disconnect the idle actuators, bike overheating.

Cheers.

Yes - def worth the time to sync. I just did mine on my 2012 with 60k miles on it, and it made quite a big difference. I just used 20’ of 1/4” clear tubing nailed to a board and some ATF. I don’t own a GS911. I read on another forum that you don’t need to bother with parking the idle actuators, and you don’t need to TB sync at idle, either. Just work on balancing them around 3500-4000 rpm and you should be good to go across the range. The idle actuators evidently take care of themselves.

Total cost for parts to build my balancer: $18. Time required: 20mins (including getting bike warmed up). Value of doing it myself: priceless. Just do it!

 

[Mistacat]

I always lock the idle actuators with the GS911 and balance the throttle bodies just as it comes off idle.
The Idle actuators do not have a feedback circuit to the ECU and they are both linked. The ECU does not know what they are doing and where they are, unless you calibrate them.
It would have been nice if BMW had incorporated 2 separate MAP sensors so that the idle actuators were individually controlled by the manifold vacuum.

 

[Mac One]

I always lock the idle actuators with the GS911 and balance the throttle bodies just as it comes off idle.
The Idle actuators do not have a feedback circuit to the ECU and they are both linked. The ECU does not know what they are doing and where they are, unless you calibrate them.
It would have been nice if BMW had incorporated 2 separate MAP sensors so that the idle actuators were individually controlled by the manifold vacuum.

The problem i have with that is the GS911 won't lock the actuators until the engine is at operating temperature which doesn't leave much time for adjustment before it overheats. ( I haven't got a fan )

If you were to go down the unplugging the actuators road, when would be the best time to unplug them to get the best results, before you switch the ignition on, after you switch on, or switch on then off and then unplug.

I assume at some point during the start up sequence they are close to the position the GS911 locks them in for TB sync.

Cheers.

 

[Mistacat]

It does not take many seconds to adjust the cables.
I apply a little sideways pressure to the outer cable near the TB this shows which one to adjust.
I usually adjust that one clockwise so that it maintains free play in throttle.
Start at 80 degrees and easily done before 100 degrees without a fan.
Not sure about unplugging the actuators as the GS911 calibrates them before locking them.

 

[Mac One]

It does not take many seconds to adjust the cables.
I apply a little sideways pressure to the outer cable near the TB this shows which one to adjust.
I usually adjust that one clockwise so that it maintains free play in throttle.
Start at 80 degrees and easily done before 100 degrees without a fan.
Not sure about unplugging the actuators as the GS911 calibrates them before locking them.

Cheers, thanks for that. I think on earlier models you could see or feel the free play at the cable ends which is not the case with twin cams. The sideways pressure is a good tip.