I have a PB 650 blower, and just recently, it has sounded like it just is'nt quite getting to full power at full throttle. I know on my other blowers, there are needle valve adjustments to "tweak" it for optimum performance. This unit does not have the needle adjustments on the carb. I'm going to check the pick up filter in the gas tank, but did not know if anyone else has run across this. Any suggestions? And while I'm asking. Why does'nt the PB 650 have the adjustment needles on the carb?