My echo srm 210 will not excelerate?

Either your throttle cable is broken or disconnected. The cable has like a ball with flat sides soldered on both ends that connect the carb to the trigger. If that comes out of either the carb or the trigger it won't work. If that is in place on both ends it maybe be broken or very frayed in the middle somewhere. If you can't see if it's broken, disconnect it from the carb and pull on it, if it comes out it's broken. They really aren't repairable, you'll have to get a new one the correct length for your machine.