Knobs are a bit more work. If they can't be taken off or appart in some way; use a good oil, let it seep in, tilt the macine in a direction that allows the oil to seep down and in where it might do some good. As you know it's all about persistant and repeated action; oil, gently push in and turn the knobs, let the oil seep in and do its' job, then more oil, push and turn it to its' extreme positions... Let it work over night and keep it up at least once a day until it loosens up. You can use a good spray can oil to start with, it will help loosen dried up grime and dirt, and then perhaps switch to smomething with teflon like TriFlow or Finish Line Ceramic Wet Lube (the only two products I have found to be an improvment on the basic oil).
Last edited by Mickey2; 06-10-2017 at 03:40 PM.