Does Pro mix 2 cycle stop up weedeaters?

If you don't use the correct gas/oil mix ratio.

I have worked in the industry for 30 years, Never seen it when properly mixed. Most issues when fuel to oil ratio is off. Not enough oil and you risk burning up main bearing, too much and the machine will not run properly. Most of the time a gummed up weed trimmer is due from setting with old fuel in the tank and lines.

No works fine in my weedeater and cultivator

i can tell you that it has no ill effects on any equipment, i use it in weed wackers, chain saws, my lawn boy push mower, as well as various atv's. anyone who says different is either not knowlegeable or not aware of a carberator in need of cleaning. it is only a matter of time until a carberator will become dirty with some small particles. it is really easy to clean and if you do it every 3-4 years, and take care of your equipment keeping filter s clean and such you will have no problem.