Never thought I'd ever be doing this again.
My son's father-in-law recently bought a very pretty, blue and white, K1200RS that had been whacked from behind by a car.
Low miles and good condition. Must...not...weaken. 
Only damage was a silencer that was pointed a few inched higher than before and a bit of a scrape to the left side of the fairing when it fell over.
The accident damage is now sorted but there have been a couple of niggles that I'm hoping someone might have an answer for.
First was vibration at 80mph and above but a change of drive shaft solved that. Not uncommon, I believe.
Other problem was a rough tick over. I had suggested that one of the blanking plugs on the injectors may be missing or accidentally stuck on one of the butterfly adjusting screws. What sort of dipstick would ever do something like that! 
When he removed the panels and had a look he said that one of the pipes had pulled off the TB where the TB's were linked together by a series of 'T' pieces and lengths of pipe? Seen this bodge done on jap multis to make them tick over more evenly without balancing the TB's.
Anyway, said it's now ticking over much better than before. I told him to throw them away, put blanking plugs on and borrow my gauges next time he takes the panels off.
The question I'm not sure about, and I don't think this bodge would cause it, is very little engine braking when shutting off the throttle.
He is finding it very unnerving with such a heavy bike when coming into corners.
On the K100, the TPS cuts off the fuel until it's back down to 2000rpm and this does give it a considerable amount of engine braking. As some of had tried, if you unplug the TPS it makes the engine braking less extreme and some prefer that.
I know that the TPS on the K12 is a bit more sophisticated than the K100, as is the fuel system itself.
Is there very little engine braking on the K12 engine? He has had jap fours before, so it's not as if he has been used to big twins.
Or could someone have been messing about with the TPS? Can it even run with the TPS disconnected?
Any thoughts?

My GT & previous RS have had plenty of engine braking on decelleration. There is a length of hose on the back side of the TBs which redistributes the engine oil vapour. These are feeble and cause weirdness at idle if perished. They're a cool hundred dollars from BMW, but close inspection will reveal that it's not terribly difficult to roll yer own. I've replaced two of three, and not at high mileage.

Comberjohn wrote:.
Or could someone have been messing about with the TPS? Can it even run with the TPS disconnected?
Any thoughts?

I thought that with the Motronic the bike wouldn't run without the TPS.

If you can borrow a GS-911 you can check and set the TPS.

Mike

A bit more research reveals that the K12 actually has a system of pipes and 'T' pieces connecting the injectors.
The air bleed screws that are on the K100 are blanked off.
You would wonder why this was not the case on the K100 from the start?
He wants me too take it for a spin to see what I think ref engine braking.

.See my post above....and a servo motor regulates idle through the Motronic 2.4. A K100's LE Jetronic and the earlier Motronic aren't that sophisticated.