Sounds like you will need to clean your carburetor, or rebuild it. Could be some debris in the jets of the carburetor. If the blower is over a couple years old, then I also recommend that you buy and install a new carburetor repair kit, because the diaphragm will get hard and that will cause it to be hard to crank and not run at full speed. Hint: When you clean your carburetor and remove the jet screws, count the number of turns it takes to seat the jets from their original position. That way when you go to put the jets back in, you know how many turns they were in/out. Please rate me, Thanks Good Luck, I hope this helped