Open the fuel cap on the top of the motor of the Ryobie EX26 and pour fuel into the tank if it will not start. If you see there is fuel already inside, close the fuel cap and press the primer button on the side of the motor until you see fuel inside of the bubble. If you do not see fuel, the fuel lines may be blocked.
Move the "Start" lever to the "Start" position if it isn't already and squeeze the trigger and pull the rope to attempt to start the Ryobi. If there is fuel in the tank, the engine compartment may be flooded with fuel. Continue to pull squeeze the trigger and pull the rope multiple times until it starts. If it doesn't start after numerous attempts, you may have an engine or fuel line issue.
Ensure that the fuel you are using with your Ryobi is the correct mixture of gasoline and 2-cycle lubricant if the engine sputters or smokes while in use. The mixture should be 50:1. If it isn't, let the engine run until all fuel is used in the fuel tank and fill the tank with the proper mixture. If this doesn't solve the problem, you may need to replace the air filter or your spark plug.
Use a straight screwdriver to turn the "Idle Speed Screw" located on the side of the motor clockwise to increase the idle speed of the Ryobi if the engine starts but cuts out while idling. Start the trimmer after you have made the adjustment to see if you need to increase or decrease the speed. If changing the idle speed has no effect, you may have an internal engine problem.