Stihl 084

[Kidneycutter]

Haven't bought a chainsaw for ages - very difficult to justify to my wife why I need so many!
Anyway got this for next to nothing, took the exhaust off and the piston looks pristine and the machine markings clearly visible.
She started after a few pulls but can't stop the chain moving without it stalling - obviously I've closed the throttle butterfly when backing off the idle screw.
Don't have much experience with these big saws but I can normally tune a saw without a problem. I can't adjust it to idle - it doesn't idle eractically just engages the clutch.
Help....please

 

[cus_deluxe]

grease the sprocket bearing. or needs clutch spring/s

 

[Wood Doctor]

As said above, likely the clutch springs are weak or one is broken. I've run into both of these cases. As such, it will even drive the chain around the bar at low idle. Grime and gunk could also be trapped between the clutch and the sprocket and must be cleaned out.