My McCulloch (model 600134140)20" chainsaw's automatic oiler has completely stopped working. Also, the manual oiler works, but is very hard to depress - about wear your thumb out trying to push the button in. Seems like the manual oiler becomes harder to push as the saw warms up.

I have tried blowing compressed air into the oil outlet and rinsed out the oil reservoir with fuel in case there is trash in there.

Anyone got any ideas? Thanks - Glynn