stalling during downshift

[1200bc]

I just bought this 2001 r1150rt a month ago. It has a Remus exhaust and K&N air filter. The bike has under 20,000 kilometers on it. I was told it had the 20,000 service done when I bought it from the dealer. It stalls during downshifts when I let off the throttle. Very scary going around corners.This is the first BMW I've owned. Any ideas?

[Juan_in_a_million]

I just bought this 2001 r1150rt a month ago. It has a Remus exhaust and K&N air filter. The bike has under 20,000 kilometers on it. I was told it had the 20,000 service done when I bought it from the dealer. It stalls during downshifts when I let off the throttle. Very scary going around corners.This is the first BMW I've owned. Any ideas?

 

Hi,

that's not typical BMW behavior. I'm assuming that the engine was warm at operating temperature. I would check the iddle speed and TB synchronization.

cheers!

Juan Antonio

[scottie_boy]

How does it run other than the stalling? Does the bike have a Power Commander or Techlusion EFI boxes? These bikes come from the factory running very lean. If the previous owner installed a K&N filter and Remus exhaust and didn't compensate for them, they would only make the bike run even leaner. That might be the source of your problem.

[ShovelStrokeEd]

Before you go off setting valves and adjusting stuff like throttle synchronization, or God Forbid, adding whiz bang electronic devices to your bike, make a simple check of the throttle position sensor voltage. Use the search function here and search on TPS going back a year or two. You should have about 380 to 390 mV at idle. The search results will also yield procedures for measuring and adjusting, if needed.

[Nevets]

If you don't mind, I'd like to find out what you determine to be the cause of the stalling. I have had a similar symptom. It has stalled after releasing the throttle after getting off the highway this winter, and once or twice afterunder similar circumstances. I seem to have partially "fixed" it by doing a LBS cleaning and throttle body sync. However, I still have what seems to be a rough idle and am unable to keep the idle speed set at 1100RPM. Have not adjusted the valves yet. I think it may have something to do with an air leak upstream from the throttle body, but am not sure yet (no time yet to put in new o-rings). My TPS reading measured right where it should be. Hope to have some able fellow riders help me diagnose it at the upcoming Detroit Tech Daze. Good luck!

[DEF]

You might also try cleaning the TBs (the insides) with carb spray. If dirty, they can choke off air even though the TPS voltage Ed refers to is correct.

[ShovelStrokeEd]

Good point, especially the right side TB as the crankcase vent dumps into the air box near its bell mouth. Wouldn't hurt, while you have stuff that far down, to pull the top of the air box and clean any grunge from the area inside as well.