Synchronizing R1100 Throttle Bodies - Bob Gorman - BMW R850 Maintenance Manual

inlet tract of the right throttle body towards the input of the LOWER "supply"
plastic distribution line.
15. NOW THIS IS IMPORTANT! Cut the remaining hose to allow a smooth
generous arc that contacts the cylinder finning and does NOT interfere with
throttle operation. Start longer than you think and trim a little at a time to allow for
a smooth arc and NO throttle mechanism interference on the right throttle body.
Now install your last new clamp at the LOWER "supply" plastic distribution line.
16. RECHECK ALL WORK, SANITIZE THE LAYOUT, RECHECK THROTTLE
OPERATION, DOUBLE CHECK ARROW DIRECTION ON THE FILTER!
17. If all looks OK, start the engine and check for leaks.
18. Test ride the motorcycle. After the ride, AGAIN check for throttle interference.
If you made the forward loop long enough the hose will generously clear the
throttle mechanism.
Well, that's it! You can now change out the filter in minutes and with no hassle.
You will never have to go into your tank again. The aftermarket Deutsch filter is
cheap, works fine, and encourages replacement every major service at 12,000
miles—a good practice. The Deutsch also works fine in Ks.
ONE FINAL NOTE:
I personally thank noted wrench Joe Katz for this "loop" installation method, for
which I give him full credit. I had originally installed a much smaller filter along the
"supply" line without a loop above the right throttle body. This seemed to work
until I observed that the Fram 3606 filter I was using at the time would inhibit fuel
flow at wide open throttle, dropping fuel pressure and causing fuel starvation
initially on the right cylinder—NOT good! Curiously, the similarly sized Deutsch
FF330 I previously had installed didn't cause this. Anyway, I wanted to use the
larger OEM size filter but couldn't see the obvious "Katz" solution. Thanks, Joe!
As always, questions are welcome. Happy Wrenching!
Editor's Note: R1100GS/1150GS riders are placing the external fuel filter on top
of the air box.

Synchronizing R1100 Throttle Bodies - Bob Gorman

This is and will continue to be a hot topic amongst R1100 owners. Properly
synched throttle bodies will greatly reduce surging and vibration but getting them
synched and keeping them synched is probably the most difficult of any BMW
motorcycle to date. Dealers were required to purchase a $1000.00 special
instrument in order to properly synch the big twin but it can be done with the
conventional Carb-Stix. It is easier with the special tool which electrically
dampens the sensitivity of the throttle operation but I have had very good luck
with the Carb-Stix for over 50,000 miles.
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