Owning a super pocket bike is similar to owning a full sized motorcycle. There are going to be times when you have to change the oil, switch out a few parts, and give it an all around tuning. We have some great tuning tips that you should do every few months. This is going to keep it running great and hopefully keep you from having to purchase brand new parts when something goes wrong.
Marking the throttle is going to be an important thing for you to do. In order to do this you have to put a whiteout mark on the front of the housing (or the side farther away from you when you sit down) and another mark aligned on the throttle grip. This will show you when the throttle is completely closed off.
Open the throttle all the way and place a mark on the housing that lines up with the mark on the throttle grip. This is going to be near the back of the housing (or the side closest to you when you sit down). Place three more evenly space between the first two marks. These will represent the ¼, ½, and ¾ throttle. It will be easier to make adjustments in this way.
Now adjust the idle screw that is used to regulate the fuel/air mixture from the no throttle to the ¼ line. Start up the engine and allow it to warm up for a few minutes. Once it is warmed up use a flat head screwdriver to turn the carburetor idle screw into the throttle valve. Now turn the screw in either direction until the engine has attained the max RPM. When that happens immediately turn the screw back until the RPM is down to 1,000. Do this twice.
Now adjust the needle and needle jet that will regulate the fuel/air mixture from ¼ to ¾ throttle. To do this go for a ride on an empty road and keep the throttle open at the ¼ mark. As you drive slowly move it to the ¾ mark and listen to how the engine sounds. Move it back down to ¼ and quickly shift it to the ¾ mark. It should sound lean.
Now adjust the main jet that regulates the fuel/air mixture from ¾ to full throttle. The main jet will have a hole that has the ability to control the fuel flow. These jets come in varied hole sizes. Begin with the main jet that has the biggest hole and work your way to the smaller holes until you find a jet that’s just right for what you are looking for. You can do this by going on a test ride with your throttle between ¾ and wide open, then going to full throttle for a whole minute.
Listen closely to the engine. Slow down immediately if your engine sounds lean. However, this shouldn’t be a problem since the large hole will make your engine run rich. To lean out the mixture, switch to the jet with the next smallest hole size and continue testing with other smaller jets until the engine is at its best between ¾ and full throttle.