Small Engines (Lawn Mowers, etc.): Gas Powered Pressure Washer Wont STOP, sears craftsman, spark plug wire

Question
I have a small 3.75 horse Sears Craftsman gas powered pressure (Sears item #07175200000)that I absolutely love, except for one problem--I can't turn it OFF!  I have to resort to pulling the spark plug wire off to stop it.  What's causing the trouble and how do I fix it?

Answer
It sounds like the shut-off switch may be defective or disconnected.  You'll have to check first to see if the wire has come off anywhere between the switch and the coil.  If it hasn't, you can take the wire off the switch and check it with an ohmmeter to verify that it has continuity to the switch's case (threads) when the switch is in the "off" position and replace if faulty.  Hope this helps.