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Throttle body sync R1200rt

B

bmw4life

Guest
Hi All,
I am getting ready to do throttle body sync on my bike and need some clarification.
Do I need to disconnect the stepper motor prior to doing the sync for varying RPM?
I donÔÇÖt believe it is possible to do any throttle body sync at idle?
Any guidelines/steps to do the throttle body sync on the R1200rt?

Thanks
 
There has been some debate about whether or not you need to disconnect the stepper motors. I never bother. I use the following procedure:

-Bike should be warmed up with tupperware removed to access TBs.

-Put cooling fan in front of bike.

-Hook up Twin Max or other measuring device to the vacuum ports on the throttle bodies.

-Start engine.

-Rev bike up to 3000 RPMs (hold steady RPMs) and use right side TB cable adjuster to sync the two sides so they are even.

-Lock down adjuster cable lock nut and re-check.

-Remove Twin Max and reconnect vacuum port with hose (left side) cap (right side)

-Go ride.

I've found it much easier than performing the procedure on the R1100.
 
The TB idle adjusters "track" each other - ie - they don't open unevenly, so there is no advantage to disconnecting them. The latest Beta version of the GS-911 software either has, or will have the capability of "parking" them - but that also is really not needed.

What is needed is to adjust the balance at the most critical small angle opening. I'd suggest 2,000 RPM rather than 3,000.. the smaller the opening, the more any imbalance is going to show up.

That said - so far I have not had to adjust my throttle bodies at all. With my Twinmax on MAX sensitivity - they appear perfectly balanced between 2,000-6,000 RPM (and probably higher, but I don't like to rev the engine without a load on it higher than 6k..) They are about 1 division off at idle - but from everything I've read - this is common and not unusual, and nothing to be concerned with.

The trick is - make absolutely sure your valve adjustment is spot on BEFORE even checking the TB sync. Chances are very good if you get the valve adjustment right, you won't have to touch the sync. It seems the short and direct cable routing on the R1200XX series engines is much more stable than the earlier R11 series design was. I haven't touched it in 24,000 miles.
 
Throttle body sync

Hi, Thanks for all the feedback.
I am confused do I do all the adjustment on the throttle body cable (right side-throttle side) only? Do I need to do any adjustment on the throttle cable on the clutch side?
I looked at Jim Von Baden instructions in his website and he has the following comments

"Note: Before starting the adjustment process, make sure you have at least 1mm slack in the cables, and never adjust one side so that all the slack is gone. If you remove the slack, put it back and go adjust the other side to sync. "

Please let me know.
 
I only adjust the cable on the right (throttle) side of the bike. I do not loosen any cables first (like I do on the R1100's) I've only had to adjust the cable about 1/4 of a turn to get it to balance so it's not necessary to use the adjuster on the left side of the cable. The instructions you quote from Jim's website seem more applicable to adjusting the older R1100/1150 bikes. Jim would have to comment on this since I do not know for sure.
 
The TB idle adjusters "track" each other - ie - they don't open unevenly, so there is no advantage to disconnecting them. The latest Beta version of the GS-911 software either has, or will have the capability of "parking" them - but that also is really not needed.

What is needed is to adjust the balance at the most critical small angle opening. I'd suggest 2,000 RPM rather than 3,000.. the smaller the opening, the more any imbalance is going to show up.

That said - so far I have not had to adjust my throttle bodies at all. With my Twinmax on MAX sensitivity - they appear perfectly balanced between 2,000-6,000 RPM (and probably higher, but I don't like to rev the engine without a load on it higher than 6k..) They are about 1 division off at idle - but from everything I've read - this is common and not unusual, and nothing to be concerned with.

The trick is - make absolutely sure your valve adjustment is spot on BEFORE even checking the TB sync. Chances are very good if you get the valve adjustment right, you won't have to touch the sync. It seems the short and direct cable routing on the R1200XX series engines is much more stable than the earlier R11 series design was. I haven't touched it in 24,000 miles.

My RT was out of sinc from the factory, I bought the bike at 1800 miles with the fault disclosed by the seller. Bike still under warrentee but the BMW dealer quoting the party line said the "idle balance screws are factory set and sealed, are never out of adjustment and are not adjustable".
They quoted $850 for new thottle bodies.
Not impressed with this arrogance I put the bike on my own bench. My twin max showed the right TB was leading the left. This was the cause of difficult starting and a very rough idle with loads of clutch knock.
I commited the horrendos sin of breaking the paint seal on the right TB screw and adjusted it down, (closed) untill the twin max balanced, now it would not start at all so onto plan B. I disconected all electronics from the TB's. Engine started but idle was at 2100 rpm. Closed down both TB adjusters untill idle dropped to about 1650 at which point it would come no lower despite further lowering of the adjusters. I balanced them out on the twin max just at the point where they were contacting the throttle plates, tiny increase in revs.
On reconnecting the electronics the idle dropped to factory spec, starting was instantaneous, idle was smooth and even.
Only the TB screws were maladjusted at the factory, the cable balance was spot on according to the twin max. 6000 miles later, all it is still spot on.

Roger Slater
 
Only the TB screws were maladjusted at the factory, the cable balance was spot on according to the twin max. 6000 miles later, all it is still spot on.

Roger Slater
Roger, when you say TB screws - can I assume you're referring to the stop screw for the butterfly?

Interesting. Wonder why BMW wouldn't just replace the TB's under warranty for you. It would seem this should only effect idle performance.. ??
 
Roger, when you say TB screws - can I assume you're referring to the stop screw for the butterfly?

Interesting. Wonder why BMW wouldn't just replace the TB's under warranty for you. It would seem this should only effect idle performance.. ??

Yes Don, I am indeed refering to the stop screws that control the butterfly position.
I have no technical explanation of why my method worked, I simply relied on my years of practical experiance which assumed that if the electronic controlers are taken out of the picture what is left is a simple mechinism that is no different to put into sycranisation as one would a pair of Amals on a fifties Triumph.

A warentee request did not get as far as BMWNA, The dealer service manager chose to not believe my explanation of the bikes history. The sticking point being the mere 1800 miles over two years with no record of the bike being taken back for rectification in a timely manner.
My explanation that the first owner was so disgusted with the bikes hard starting and rough idle he tossed it to the back of the shed and bought a Harley. The 1800 miles was one single trip from the midwest selling dealer to the owners home in Maine. It was not started again untill I recived it.

Roger
 
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