Classic sign of coil failure. Run it until it cuts off then test the coil. Most likely 0 resistance, complete open circuit. This is common, coil can't be repaired, only replaced. It is a simple fix, and echo trimmers I believe are worth the cost of coil to repair. Plenty of youtube videos on how to do this repair.
Could be fuel tank not venting properly. Run until the symptoms repeat then loosen fuel cap. If it starts and runs ok then likely the vent (cap?) Is plugged.
There is no special tool. The bolts are hex heads are require a hex tool to remove them. These can be found at any auto parts or home improvement store. Also, just an FYI, the head and cylinder are on piece on this model.
Press the primer bulb several times. If no fuel in bulb, identify the fuel line that connects to fuel filter inside of the tank. Verify filter is connected and no cracks in line.
Then disconnect the other fuel line (fuel return) at the carb. Pump the primer several times. If still no fuel move the fuel line at the carb to the other port. Leave other line off (for now). Pump primer several times. If fuel pumps, fuel lines were connected wrong. Connect return line... start.
Secondary winding (spark plug wire) to fame 2k to 8k ohms. If infinity (open), then look for break in wire or boot, else internal secondary winding has failed.
This an ignition module so primary winding is not accessible. Check ignition kill wire. Disconnect kill wire at module and measure continuity of kill wire to engine frame. With Run/Stop switch in STOP position it should read zero ohms (a short). In RUN position it should read infinite ohms (open).
