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Thottle Body Synch


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When the valves are adjusted at every 6000 mile service is normal. An R11**RT takes some time to do because of the tupperware. A warm naked bike should take around 10-15 minutes to balance the bodies with a TwinMax unless you have throttle cable issues.


Some of the signs of a throttle body balance being needed are if you notice your mirrors vibrating strongly on a well warmed up bike, or quite strong vibrations through the bars when riding. When my bike is right, the bars almost massage your hands and the mirrors are almost completely still at idle.


I hope this helps,


Linz :)

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How often is it required to do a throttle body synch on an '04 R1150RT ?


How would I know this needs to be done, what are the symptoms ?


After my 04RT got about 18K miles on it I decided to not worry about valves or TB sync except every 10K miles or sooner if something begins to feel not right. I change oil and filter every 3K miles as well as FD oil same time. Only reason for FD oil change is I'm paranoid after reading about all the FD failures. I wouldn't hesitate to let the TB sync and valve adjust go to maybe 15K miles, again, as long as all seems good. If it were not for the internet and these m/c forums I would think my 04RT to be absolutely the most bullet proof bike I have ever owned. Large quantities of information can have affects on one's mind.

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Once a bike is thoroughly bedded in (which I would imagine to be the case on a 2004 RT), I can't imagine the throttle body sync changing significantly if you're only doing routine maintenance (oil changes and valve adjustments).


BUT... this assumes that the sync is correct to begin with. As a new BMW owner, I had the dealer do the 66,000 mile service. When I did my first tech day last month, I found that the lock nut on the right side cable adjuster wasn't even tight -- in fact it was backed off about a quarter inch. After 30 minutes of fiddling, I got the throttle bodies synced as close to perfectly as I could, and the engine is noticeably smoother at all speeds, idles better, and backfires less. Do the job yourself, on your own time schedule, and get a better result than you will from a dealer.

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Thanks for the advice.


I just bled the brakes and am getting up the confidence to adjust the valves myself. I don't notice any excess vibration but will check the TB synch anyway.

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There is a great TB Sync for Dummies guide on ADVrider Hall of Wisdom (at least I think that is where I got it from). Based on that, I always do the valves first before I start with the TB sync. If you're brave enough to do a 04RT servo brake bleed with the tank off, you won't have any worries about this.


By the by... I didn't notice any vibration in my bike either until I did the valves and TB sync myself and then realized how wrong I was. Of course, now that I know what "perfection" is... What's the saying, "Ignorance is Bliss" :grin:


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I'll check out the hall of wisdom for TB Sync instructions. I have some time off over the holidays which would be a great time to do the valve adjustment / TB sync.


However, theres the matter of my daughter's bathroom that we gutted last summer and needs to be finished (new tub, sink, toilet, tiled walls, etc, etc). A couple people here won't be happy if they see me wrenching on the bike until thats finished !



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If I come back from a weekend ride and I think the bike didn't run quite right. I have "my boy" sinc them on Monday. The RT's are a little harder but the GS is easy. When in doubt I check.


because of this I just found my wife's R1100R has a vacume leak. the dealer was the last one to do the sinc however the two brass screws are 2 1/2 turns apart. acording to the instructions they are supose to be within a half turn. instead of fixing the leak they just put more turns on the screws.

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Ok, so...


I did a TBS a couple weeks back, and my gas mileage took a dump on me, going from mid 40's to hi 30's. In trying to fix it, I found that I a stripped cable adjuster on the right side so I replaced the cable.


I just did a TBS today after replacing the throttle cable on my 1996 R1100RT. The bike runs good and I was able to get the bike pretty well in tune according to the twinmax.


However, the BBS are about 2 turns apart. So... my questions are these:


1. If my right side TB is at about 1 turn out, and the left (TPS side) is at about 3 turns, what is my course of action? How should I troubleshoot this to get them back closer together?


2. Is that likely going to mess with my mileage?


3. What do the BBS actually do? I'm used to carburetors and mixture screws, so, I would presume that these adding/reducing air, yes? Does farther open means a leaner mixture?

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Sounds like the same thing I found with my 04 RT. Try taking the BBS out and cleaning them and then shooting some cleaner down the holes they came out of. Of corse them ya gotta start all over with the synch. Mine went from over two turns different to within a quarter turn different by doing that.


I believe you are right that the BBS will change the air flow at idle. I don't think that will make them leaner as the fuel injection will add more fuel to make up for the increased air flow.


Can somebody else chime in here and tell me if this is correct? :lurk:

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Thanks Duck!

I was thinking they probably needed to be cleaned out as well, I don't know how long they had sat, and I didn't touch them for about 10K miles, I admit...

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