I have a set of echo trimmers Model hc-150 that have recently become a pain in the a$$ to get started. They only crank when they are almost completely choked out and only run when they are full throttled and almost completely choked out. I'm pretty sure its a carb issue. There is no idle, low, high adjustments so I am wondering what I can do to fix my problem. Any help would be much appreciated. Is it me or are hedge trimmers the hardest power tool to keep functioning properly? After all they are the one tool that isn't used every day.