Can I take a weed eater motor and put it on a scooter?

I have an electric scooter, but i want to mount a weed eater motor on a it, can it be done? what do i need? and can the motor idle?

Yes, it can be done. The main problem is idling. You'll have to install a clutch, of some kind. Most small vehicles, like this use a centrifugal clutch that engages friction when you increase the engine revs. It has a drum that expands via centrifugal force and engages with a belt drive as the revs are increased.

You could also fabricate a simple tension clutch. Make the final drive belt loose, and increase the tension with a capstan in the center of the belt, pulled outward from the center by a cable engaged at one of the handgrips. You can adapt an old bicycle brake to do the job. The advantages of this approach are you can do it for a lot less then the $80 - $100 a centrifugal clutch will run you, and a manual clutch will probably be more fun, anyway.

Other then that, it's just a matter of determining the correct output ratio for the engine you're using. A bigger drive pulley at the engine will increase the output ratio, and give you more speed, but less starting torque. A small pulley, or a large one at the drive wheel will make you go slow, but will give you the ability to conquer steep hills. You'll probably have to experiment a bit to find the right ratio. Besides that, all you have to do is run a throttle cable up to the handlebars. The starter pull and the kill switch are probably already on the engine, which is fine for a scooter.

Yes it can be done, I'd recomend that you check on the web for what will be needed to complete your project.

yes

Yes, you can have motor idle with a centrifical clutch. Use chain or v-belt for the drive.

Yeah, you can. But I would suggest a motor a little bigger, like a chainsaw motor for more torque (pushing power). Some kinda brake would probably be useful too. The original one is likely not sufficient.