HouseCallAuto 4/12/2010The fuel filter is inline where the fuel line attaches to the front of the carburetor. I would replace the fuel filter first. The filter is small compared to how fuel filters are in size now with fuel injection systems. They clog and rob the power under load like you describe. The best part is that the fuel filter is like 3 or 4 dollars but be careful changing it yourself because the threads on that fitting that you need to remove and replace are very fine and there is a plastic ring gasket that needs to sit just right. I have seen many people over the years cross thread the fitting and then you need to replace the carburetor and that is expensive.