Small Engines (Lawn Mowers, etc.): weed eater wont stay running, weed eater, diaphram

Question
I have a weed eater modle XR-85. I can get it to start and keep it running if I keep pushing the fuel injection button.It is like it runs out of gas, like it's not getting gas. All the gas lines are new and gas runs thru them. The carb is clean. What can it be?  

Answer
If it isn't a tank vent issue (open the cap slightly and see if this corrects problem), there is still an issue with the carb.  Not sure about your model but you would also need to verify the impulse hose from the crankcase to carb doesn't have any holes in it.  This provides crankcase pulse to operate the fuel pump diaphram in the carb.  Otherwise you will need to thoroughly clean the carb including pushing a piece of tag wire through all of the interal passages and follow up with carb cleaner.  Hope this helps.