Jetting CR125 Shifter Kart

Version 2.1 • Apple Watch, widgets and Live Activity: your main jet for right now on your wrist, on the lock screen and in the Dynamic Island throughout your track day. • Track mode: your jetting large and high contrast, to read it in full sun with your helmet on. And dark mode throughout. • Alerts when the weather changes enough to change the main jet: "Air density has dropped by 1.8% since your last calculation". • Fuel: 98 E5, E10, E15, ethanol-free, CIK-FIA or race fuel, and the jetting is corrected for it. • Carburetor icing warning, using the criterion of civil aviation. • Fuel and oil mix calculator. • When you fetch the weather, the app detects the track you are at. 144 tracks in 22 countries. • Logbook synced through iCloud, and your jetting shared with your mechanic as a link or a QR code. • Fine tuning changes the jetting again, and the pilot jet is chosen from the sizes Keihin sells. • Location also works on iPad without GPS and indoors. • Report a problem and rate the app, from Results and from Help. IN EARLIER VERSIONS • 2.0: run logbook with ratings for low, mid and high, laps and RPM; tracks with the altitude of the track itself, the US ones first; the weather station and the values you type in on a single screen; the app full screen on modern iPhones.

The only jetting app made for the Honda CR125 shifter kart. It works out the jetting of Stock Moto and Mod Moto engines with Keihin PWK 38 and PWM 38 carbs, from the real temperature, humidity, pressure and altitude, and from the fuel you use. WHY THIS APP • Made for the CR125 shifter kart: Stock Moto and Mod Moto, fuel pump and airbox, which change the jetting and go into the calculation. • Apple Watch app, widgets and Live Activity: your main jet for right now on your wrist, on the lock screen and in the Dynamic Island. • Track mode: your jetting large and high contrast, to read it in full sun with your helmet on. • It alerts you when the weather changes enough to change the main jet, using the hourly forecast too. • It takes your fuel into account: E10, E15, ethanol-free, CIK-FIA or race fuel. • Carburetor icing warning, using the criterion of civil aviation. • 144 tracks in 22 countries with the altitude of the track itself, the US ones first, and it detects which one you are at. • A run logbook synced through iCloud, and your jetting shared with your mechanic as a link or a QR code, with no accounts. ENGINES Stock Moto and Mod Moto, with a clamp-on air filter or an airbox with or without foam, and with or without a fuel pump. RESULTS The recommended jetting for your conditions and your engine: main jet, needle type and clip position, and pilot jet, plus air density, density altitude and relative horsepower. Three ±10% fine adjustments, on high, mid and low, to match it to your engine and how it is built. The values assume a #6 slide. FUEL 98 E5 (93 AKI), E10 pump gas, E15 (Unleaded 88), ethanol-free, CIK-FIA, leaded race fuel, race E10, oxygenated, or your own with its stoichiometric ratio and density. With E10 the main jet goes up by about 1% compared with 98 E5. Octane does not change the jetting; ethanol does. CARBURETOR ICING From temperature, humidity and the chart civil aviation uses for carburetor engines, the app warns you when there is a risk at full throttle, and Conditions tells you whether there is one at idle and on the grid. TRACK MODE AND TRACK DAY Your jetting full screen at maximum brightness, how much the density has changed since what you fitted, and how old the data is. When you start a track day, for 12 hours the main jet is on the lock screen, in the Dynamic Island and on your Apple Watch, and the app keeps an eye on the weather for you. Dark mode throughout. CONDITIONS From the nearest weather station or typed in by hand; it works the same with no signal. If you are at a track in the list, the app detects it and asks you whether that is the one. ENGINE AND FUEL MIX Engine class, airbox, fuel pump, fuel, oil and track type. Fuel and oil calculator: choose what you want to know, the oil, the fuel or the ratio, and the answer is shown large, in liters, milliliters, US or UK gallons and ounces, as a percentage and as 1:n. LOGBOOK Each run with its conditions and its jetting, then what you actually fitted and how it went, lean, good or rich, on low, mid and high, with laps, best lap and maximum RPM. It syncs through iCloud across your devices and exports to CSV. TRACKS 144 tracks with their altitude, taken from the track itself rather than the town, which are usually different. Choosing one sets its altitude and, when its length is known, the track type. Search by the track name or by the town. SHARING As an image card, as a link or as a QR code: your mechanic opens it in their app or, if they don't have it, in the browser. UNITS °F and °C, feet and meters, inHg, mb, hPa and mmHg.