Oh they will run..... the question is for how long. Weedeater motors have ball bearings and have a lower oil requirement. Glo motors may have bushings which require a higher oil content to survive. You may need to change carbs too as you have to flow more alcohol than gas to attain the same power output. Check out your setup closely so you don't burn it up.... as I recall the larger ST motors have been converted and I am sure you will find info on them.