Leaf Blowers

I own a 150BT backpack blower. AWESOME MACHINE! Bought it in 2007. Recent problem - Trigger has a lever that will hold the trigger in the full position so you dont have to keep it depressed. That is not working well anymore. After a few minutes of operation I can sense the throttle drop and when I check it is not in the full position any longer. I noticed on newer models there is a different trigger assembly. Did they have problems with the style on mine. Also at the same time I notice that when I push this same switch to the stop postion the unit does not stop any longer. I have to choke it off and then it stops after some run-on. Is there a way to fix these probs?
George Thompson