What is Surging?
 

You guys keep writing about this mysterious thing called surging... Can someone please let me in on what that is?
Thanks and apologies for my ignorance!

Surging is a is an anomoly associated with fuel injected BMW twins. Some have it worse than others. I am sure some one will come along with a more professional description, but in laymans terms: It is a surge or pulse of the engine. It is mostly felt at lower rpm. Often when putting through a town. I think it has to do with the throttle bodies being connected via cable. They are very sensitive and the cable is not. My '95 seemed almost cured, then I got a new throttle cable and it seems to be back. I think as the cable stretches and then settles in, it can then be adjusted to lessen surge. Sorry I can't explain it better.

To perhaps explain it a little further:

What it FEELS like is some moron child has his hand on the throttle - and instead of holding dead smooth and steady as you cruise through town at 30mph, is just slightly twitching it up and down - off on off on off on. Nastiness is extremely variable.

If you've ever ridden a two-stoke at a low steady speed you know all about it.

As noted the BMW fuel injection models have a problem with it. Most are fine, some aren't. Long technical dissertation follows... not.

Extremely precise setup usually cures it. Sometimes a trick or two is needed. There's tons of info on the web about it.

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Grant Johnson

Seek, and ye shall find.
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One world, Two wheels.
www.HorizonsUnlimited.com