Here is your FREE Kenmore #158.14300 Instruction Manual, which you can download at no cost directly from this authorized Sears/Kenmore manual distribution site (apparently they have 1000's of manuals to choose from.) Alway, word to the wise, why not check the manufacturer's website or Google what you're looking for
before running to these forums asking for help, obviously you didn't bother checking with the company who made your machine or Google for this Kenmore machine like I did for you, because I found your manual in less than 30 seconds after reading your question, and NO!, DO NOT ever pay for manuals when you can download them for free. There are many scam websites out there trying to rip ignorant people off by selling them photocopied or PDF/email-version Sewing Machine manuals just to make a quick buck off you. They're just printing and sending you the SAME photocopied manual anyone can easily download and print instantly from the manufacturer's website (as in this case) and they HOPE you'll never use Google search engine to easily find your manual so they can charge you for what they got for free. Don't be a sucker and pad these scammers bank accounts, they lie, cheat and steal, preying on innocent victims like yourself.
In any event, I digress, here's your manual in PDF form, for the Kenmore 158.14300 Mechanical Sewing Machine: http://www.managemyhome.com/mmh/lis_pdf/OWNM/L0909123.pdf
RunningHoove, December 2009