Main Jet Kit
Main Jets are the most critical metering system in most motorcycles. It is located at the bottom of the bowl generally near the Pilot Jet. The Main Jet helps to ensure the engine is operating under full power and prolong the engine life. The Main Jet is predominant especially in racing usage. It controls 60% to 100% of the throttle opening and provides fuel to the engine from about 1500 RPM right up to maximum RPM.
Usually, the Main Jet is the last jet you need to deal with. It is easy to get the right tune. Main Jets have different sizes of holes that determine the maximum flow rate of the fuel into the Venturi. A bigger Main Jet has a bigger hole so it lets more gas flow into the engine. The higher number of Main Jet, the richer air/fuel mixture that you will get. It is not only measures the quantity of gas into engine, it also helps in cooling the motorcycle engine.
Main Jet replacement is super easy. When you begin to adjust the Main Jet, it is advisable to start the replacement with an oversized jet. Although it will make the engine runs very rich, but it will ensure that you do not cause any damage to the engine. From there, you can gradually decrease the size (in increments of 5) of the Main Jet until your engine runs properly. Once you find the size that works well, you can make fine tune adjustments by trying different size jet around that size but using smaller increments.
Uma Racing offers high performance carburetor Main Jet kits that made from high quality steels. It is available in full sets as well as single pieces. All the jets are anodized with gold color. The full set of Main Jet for Icon bike comes with 10 different jet sizes in a carrying case, while full set of Main Jet for LC comes with 5 different jet sizes in a carrying case. This full set of Main Jet enables you to try and get the best jet size for your bike. With a properly sized Main Jet, it is not only helps to increase the engine power and smoothness ride, but also saves your fuel consumption for a long period of time.