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-   -   Bmw K1100lt (http://www.motorcycle.com/forum/motorcycle-mods-maintenance/12629-bmw-k1100lt.html)

shooberj 07-24-2009 06:48 AM

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

pushrod 07-24-2009 08:59 AM

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.

Kenneth_Moore 07-24-2009 09:19 AM

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?

shooberj 07-24-2009 09:29 AM

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.

pushrod 07-24-2009 10:27 AM

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.

SmokeU 07-24-2009 10:57 AM

What happened to the ultimate in German engineering?

The_AirHawk 07-24-2009 11:45 AM

Quote:

Originally Posted by SmokeU (Post 219721)
What happened to the ultimate in German engineering?

Eh, I wasn' gonna say nuthin'..........

pushrod 07-24-2009 01:46 PM

Quote:

Originally Posted by SmokeU (Post 219721)
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!

Kenneth_Moore 07-24-2009 02:00 PM

WHAT??!? A troll? A shriveled human hand? John Dillinger's penis? The Ark of the Covenant? A toaster?

The_AirHawk 07-24-2009 02:29 PM

Quote:

Originally Posted by Kenneth_Moore (Post 219758)
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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