I have a feather lite weed trimmer and it will not idle. When the throtle is being used it will stay running,but if I let go it will die. Also the head spins with or without using the throtle. Can a clutch be put on so as to resolve that problem

No clutch here, my trimmer spins a bit when idling. Turning down the idle screw can stop this. However since it won't idle, that's later.

If this is last years gas get new and use High Test. Carbs on weed eaters are very fussy and a hint of dirt in the carb will play havoc.

Basic causes for this problem is

1. Bad/old gas

2. Fuel filter dirty

3. Weak fuel pump

4. Dirt in carb

5. Ethanol gas being used.

If you have only ethanol gas in your area then go to a marine boat repair place and get some carb cleaner. They a have special/better carb cleaner that you can run through the carb while it runs and clean it out. They should also have an additive for gas that has Ethanol in it.

The gas additive is important for Ethanol gas users. Ethanol gas can actually ruin a 2 cycle motor.