I have a GT-1100 Echo trimmer that I'm guessing is around 10 years old. It was used by a homeowner until last summer when I began to use it to mow about 8 yards a week. Within the last week though, it has developed a problem. When I start it up, I immediately have to let go of the throttle or it will cut off. Then even after idling for about 10-15 seconds, it still cuts off. The second time I start it up, I again have to release the throttle, let it idle, and then very slowly increase the throttle until it gets to its maximum RPM. I just cleaned the air filter last week, so it shouldn't be anything wrong with the filter, but I am somewhat new to repairing my equipment (I usually take it to the dealer and have him fix it) so any help would be greatly appreciated!