Recently discussed here:

http://www.xt660.com/showpost.php?p=225857&postcount=14

In order to set it up we'd need to know what the resistance measurements are at it's terminals with the dip switches in their various positions. If you can use a multimeter to check this out we'd have a better idea of its influence on the bike's air/fuel ratio.

Alternatively you could stick the bike on a dyno and have a fiddle...

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