The master control lever will not move properly to allow me to turn the saw off, or set it in choke properly with the throttle engaged and locked. There must be something out of place or worn out that I can't figure out.
Very common issue on MS170-180 saws.Luckily it's easy to fix.Pop the air filter cover off,locate the control shaft(the part you use to turn the saw on and off),look for a flat spring.This spring should be ABOVE the control shaft.You may have to straighten the curl on the very end of the spring slightly to make it work smoothly.
What usually causes the problem is the operator not holding the throttle open when going to the choke position,applying enough force to pop the throttle shaft out of the cradle it snaps into.
I've fixed many saws with this issue over the years,it's so easy I don't even charge for it.
If you have a local Stihl dealer they might be able to help too.
Thanks for the response Don. I did drive approximately 15 miles to the closest dealer. When I took the saw in...it was working fine. He said everything looked okay. I'll check the curl though as you mentioned and make sure it's not interfering with anything.