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Hey all-

Newer BMW rider, just picked up a K1200LT awhile back and I have a mind to fix what is wrong with her. It idles inconsistently, 800-1100 and cuts out once in awhile entirely. Did some research and it looks like the TPM might be giving me trouble, I hear it is a common problem. Aside from dropping $300 on a GS-911, any other suggestions to get a diagnosis? In the Denver area. Has anyone else experienced that before? I only own older aspirated Harleys and they are easy to work on, this in my first Fuel Injected rig.

On that note, my first ride up I25 to a wedding and I was going 100+ without noticing until I came up to a nest of cagers a lot faster than I intended. Been 100+ on most of my Harleys, but you FEEL every MPH over 80. Pretty impressive ride, this 1200.

Thanks for any advice.

Jeff
 

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Welcome to the forum Jeff. What year do you have?

No, it doesn't take too much to push one of these to 3 digits.

As for your issue, there are several things that can cause this and none of them are all too easy to discern, An air leak at one of the vacuum lines ( cracked or being off the stub) is often a cause of an unstable idle. Only way to tell is to go in and look at them. The TVA hunting can happen if someone messed with the screws and the relationship between the Throttle Body and the TPS is off. Messing with the screws on the TB is not recommended as you can go south really quickly. TVA's are very simply a screw motor driving a wheel to extend and retract the TP stop. It will cycle at power on so listen for it. There is a pressure sensitive switch in the stop end.

If you get the covers off her, you can look at the screws and see if the blue paint has been chipped off, especially on the one behind the TVA. As little as 1/4 turn can cause what you are experiencing. TVA's don't go bad very often. If it is idling at all, then it is likely doing something. Sometimes in service, the TVA bracket is used to pull off the TB off the bushings and that can bend that bracket a little messing up the adjustment.

Also check the springs on the TB all along and see if someone has popped one off trying to lighten the throttle feel.

While you are looking at the springs, examine the rubber bushings supporting the TB. They can get old, dry and crack allowing excess air in and mess with the idle.

Less likely but still a possibility is an air leak in another place like under one of the intake manifolds. Corrosion can get underneath and compromise the O-ring underneath each one.
 

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Welcome to the forum, Jeff.
I noticed the same thing my first time riding the big KLT-I was cruising at 90+ mph with the windscreen at a perfect height before I noticed how fast I was traveling.
Rock steady, too!
 
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