If your quad is sluggish when your thumb hits that throttle, and you suspect jetting issues could be the culprit, try these fuel screw, air screw, and pilot jet tips to diagnose the problem. The working range of the fuel screw on a four-stroke engine is one to three half-turns out, while the airscrew on a two-stroke engine has a working range of one-and-a-quarter to two half-turns out. If adjustments outside of these working ranges improve throttle response, the culprit is the pilot jet. If you tweak the fuel screw to the upper end of the working range, richen the pilot jet; if you're working on the lower end of the range of the fuel or airscrew, lean out the pilot jet. Here's an easy tip to locate the necessary parts: Airscrews are always located on the airbox side of the carburetor slide, while fuel screws are located on the bottom of the float bowl on the engine intake side of the carburetor slide. Most fuel screws are plugged from the factory for EPA regulations, but feel free to take the plug out and tune your quad. It will really appreciate it!