I have an older Echo SRM-210 Weed Whacker that's started giving me trouble. The issues were manageable but I decided to pull it apart and clean everything... now it's worse. Essentially, it will only start if I am giving it full throttle. Then, the RPM's will get very low and I'll have no power unless I close and open the choke several times in quick succession.
If I let go of the throttle even the tiniest bit, it dies instantly.