You might find this explanation useful: http://www.phrases.org.uk/bulletin_board/14/messages/587.html

1) "[Q] From Paul Nix, UK: “Any idea of the origin of the word kilter, as used in out of kilter, to mean not aligned?” [A] To be truthful, not really. What we do know, though, is that it started out as kelter rather than kilter. In that form it was once widely known in various English and Scots dialects from at least the sixteenth century onwards. It means a state of good health or spirits, or good order. Unfortunately, we’ve no idea where it comes from. (In the interests of accuracy and completeness, there were several other dialect senses of kelter, including that of money or property, rubbish or litter, silly talk or nonsense, or — as a verb — to move in an undulating manner. The English Dialect Dictionary has a wonderful quote from a Scottish source about this last one: “Eels are said to kelter in the water when they wamble.” To wamble is to turn and twist the body about, roll or wriggle about, or roll over and over.) Sometime in the seventeenth century, the word started to be spelled kilter, for a reason as much lost in time as the origin of the word itself. For a while, both spellings co-existed — the older one appears in the 1811 edition of Captain Francis Grose’s Dictionary of the Vulgar Tongue: “KELTER. Condition, order. Out of kelter; out of order”, which also gives the money sense. Eventually, the kilter spelling mostly prevailed, though the older version still turns up occasionally." Source: http://www.worldwidewords.org/qa/qa-kil3.htm 2) ": : I believe this is an engineering term used to describe something which isnt working as precisly as it should because its out of alignment - but whats a "kilter"? : Kilter (and apparently kelter too as a rarer alternative) simply means good condition, or proper working order. Its origins are unknown, according to all the sources I've checked - there is a verb "kilt", meaning "to tuck up", but it's a little far-fetched to presume that this might have something to do with it. Making sure all the ends of one's ropes and pulleys are neatly fastened down or tucked away so that they don't get caught in the workings of some machine? I doubt it. OUT OF KILTER - " Many have tried to explain the origins of 'kilter' in this expression meaning to be out of order, out of whack, but no one has succeeded. The best suggestions I think are the 'kilter,' meaning a 'useless hand in cards,' the dialect 'kilt,' to make neat,' and the Dutch 'keelter, 'stomach,' because stomachs are often 'out of order' with digestion problems. We only know that the expression is first recorded in 1643, as 'kelter.'" From the "Encyclopedia of Word and Phrase Origins" by Robert Hendrickson (Facts on File, New York, 1997)." Source: http://www.phrases.org.uk/bulletin_board/14/messages/587.html 3) "Dear Word Detective: I've used this phrase so many times I never pondered its origin, but now I'm curious. When something seems not to be quite right, I'll say, "It seems to be out of kilter." I know what I mean when I say it, but have no idea what "kilter" is. I'm assuming in some ancient Celtic or Germanic language it meant to be "level" or "plumb" or some such builders' vernacular. Am I way off base on this? -- Scott Jackson. Dear Word Detective: Whence commeth "out of whack"? It can't related to "wacky," meaning "zany or strange," because then being out of it would be to operate normally. And where can I purchase additional supplies of whack in order to be prepared for future shortages? -- Whacking my brain, Martin Ornstein. Greetings, and welcome to That Ain't Right Week, our annual celebration of all things out of whack, out of kilter, and just plain not the way they're supposed to be. As always, this column comes with our standard 30-day warranty, under which claims for defects may be filed day or night on any day not ending in the letter "y." And remember, your phone call is important to us, so we're keeping our number a secret. Scott, your theory about "out of kilter," meaning "not in proper order or working condition; defective or malfunctioning," being derived from an ancient building term is entirely reasonable, but, unfortunately, unverifiable. We do know that "out of kilter" has a positive form, to be "in kilter," and that "kilter" first appeared in the 17th century in the English dialect form "kelter" (still used, largely in Britain) meaning "in good condition or health." But the trail is cold as to the antecedents of "kelter" and their possible meanings. And actually, Martin, "wacky" may very well be related to "out of whack." When it first appeared in the 18th century, "whack" meant simply "to beat or strike vigorously," probably formed from the sound of such a blow. "Wacky" (or "whacky") may simply liken the eccentricities of a "wacko" to the results of a blow to the head. "Whack" as a noun became thieves' slang in the late 18th century for "share of the loot" (possibly in the same sense we use "cut" today) and later came to mean "agreement or bargain." By the late 19th century, "out of whack" had come to mean "out of proper order or alignment," possibly from a further development of "whack" meaning "agreement or expectation."" Source: http://www.word-detective.com/102805.html#kilter%20whack Also cited in: http://www.answerbag.com/a_view/82001

Kilter - good working order or condition The well pump is out of kilter. [Mid-17th century. Variant of kelter, origin] http://encarta.msn.com/encnet/features/dictionary/DictionaryResults.aspx?refid=1861624067 proper or usual state or condition http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=kilter Poker, skeet http://www.infoplease.com/dictionary/kilter {slang) A person that enjoys lifting up a Scotsman’s Kilt and then fondles their genitalia. http://www.urbandictionary.com/define.php?term=kilter