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Old 07-24-2009, 05:48 AM   #1
shooberj
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Default Bmw K1100lt

Guys, or Galls, I have a problem with my K1100LT. Last weekend was a great weekend away at the MotoGP in Germany until the journey home. The bike is fine around the 80mph mark but on deceleration to lower speeds starts to cut out and 'pop'. When it is revved again it picks up and pulls up to 80 or so and is fine again, Fuel, air filters were changed recently and the plugs have been in for about 2000 miles. Any ideas would be greatly appreciated. Shooey
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Old 07-24-2009, 07:59 AM   #2
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This is totally non-bike-specific, but it sounds like you are getting a lean condition on deceleration.

A lot of bikes will pop when 'engine braking,' especially from higher rpms, but yours sounds excessive.

Two causes I can think of: manifold leak, or something wrong in the ECU/Fuel map.
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Old 07-24-2009, 08:19 AM   #3
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I'm with pushrod on the fuel mixture. Those symptoms are common when guys open the exhaust but don't adjust the intake side accordingly. Did you make any changes to the suck, squeeze, bang, or blow lately?
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Old 07-24-2009, 08:29 AM   #4
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Many thanks for the info guys, from what you say it may have just been some 'dodgy' fuel at the last tank stop. I'll give everything a good clean at the weekend and put some new plugs in, check the timing etc and let you know the results. Thanks again.
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Old 07-24-2009, 09:27 AM   #5
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shooberj,

Ken makes a good point.

Have you modified the exhaust system in any way?

Incorrectly reducing the 'backpressure' characteristics can cause all sorts of weird effects. One of them is increased popping on decel.
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Old 07-24-2009, 09:57 AM   #6
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What happened to the ultimate in German engineering?
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Old 07-24-2009, 10:45 AM   #7
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Quote:
Originally Posted by SmokeU View Post
What happened to the ultimate in German engineering?
Eh, I wasn' gonna say nuthin'..........
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Old 07-24-2009, 12:46 PM   #8
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Quote:
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What happened to the ultimate in German engineering?
I don't know about how 'ultimate' they are, but have you ever seen what is under the 'gas tank' (well, what looks like a tank, only it really is a cover) on those things?

It's a terrifying sight!
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Old 07-24-2009, 01:00 PM   #9
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WHAT??!? A troll? A shriveled human hand? John Dillinger's penis? The Ark of the Covenant? A toaster?
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Old 07-24-2009, 01:29 PM   #10
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Quote:
Originally Posted by Kenneth_Moore View Post
WHAT??!? A troll? A shriveled human hand? John Dillinger's penis? The Ark of the Covenant? A toaster?
Well, it does resemble a mish-mash of most of those........
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