The following illustrated pictures are to assist in installing new Main jets in a PWK Carb. I am assisting several individuals on this endeavor.

First, remove the two screws on the bowl. There is one screw on each side of the carbs (screws in picture appears to be on the same side, they are not). Remove the bowl carefully! You may have to wiggle the bowl a bit to avoid the captive tube attached to carb body (see second picture) and a second tube attached to the bowl.

The next step is to remove the main jet. Note the main jet's location in the picture below. The jet is made out of rather soft metal so remove carefully!

Before replacing the main jet note the size of the jet by looking at the number inscribed on the jet. Number will be a 3 digit number like "140". This number represents the size of the hole in the jet. The larger the number the larger the hole.

Replace the main jet with the desired value. Snug the new jet into the holder and replace the bowl. Again, wiggle and observe the tubes on the carb body and in the bowl. Replacing the bowl a bit of wiggling. Make sure the shaft for the float does not slide out of place and get in the way of the bowl. Snug the bowl screws up. The bowl is sealed with a rubber "o" ring gasket and does not require excessive force to maintain a seal.

For minor tweeking of Mid range throttle response, the mid range needle in the carb can be adjusted. You can obtain accesses by removing the top of the carb (see 1st picture) and pulling out the slide and needle assembly (cable comes with it!). The needle hangs down in the throat of the carb and goes up and down with the slide (also in the throat of the carb). The needle contains 5 slots or adjustments. By removing the clip on the slide and moving the clip either up or down on the needle, you are covering the hole in the throat of the carb that accesses the bowl that allows more or less gas/air into the carb.