@rcurren01, rcurren , Echo SRM-225 Trimmer, You can try with fuel cap off in case the caps vent is plugged not allowing fuel flow and or replace the filer in the tank if you have not already done so. Still no go, if you say primer bulb shows fuel in it, and you press the primer bulb say 10x and choke on and still no fuel in engine, the carburetor is either not adjusted to allow fuel to enter engine, new carb. faulty, fuel lines not hooked up properly/pinched. Links below may help trouble shoot your issue including manual. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
http://www.echo-usa.com/getattachment/7011c2f4-035a-47cb-82e5-cf7038faee8e/SRM-225es_1112_022014_2
https://www.hunker.com/12291996/how-to-adjust-the-carburetor-on-an-echo-line-trimmer
https://www.repairclinic.com/Shop-For-Parts/a26b349-x73726d323235/Srm225-Echo-String-Trimmer-Parts