Jetting for Keihin PWK/PWM/PJ

About

Work out and compare the jetting of Keihin PWK, PWM and PJ carburettors —jets, needle and clip, air screw and slide— from the real temperature, humidity, pressure and altitude and the fuel you run, for two-stroke motocross, enduro and trail bikes. WHY THIS APP • Factory jetting for 43 models from 6 brands (KTM, Husqvarna, Honda, Kawasaki, Suzuki and Yamaha, 1986 to 2027), corrected for today's weather, in a single app. • All three families, PWK, PWM and PJ, with the N427-48 needle catalogue and its dimensions. • Track mode to read it at a glance in the paddock, with the race day on the lock screen and on your Apple Watch. • Alerts you when the weather changes enough to change the main jet. • Jetting for your fuel: 98 E5, E10, E15, E0, race fuel or whatever ethanol it has. • Share the jetting with your mechanic with a link or a QR code. THE JETTING RIGHT NOW • Mark the jetting you have fitted as your reference and the app tells you, with the weather right now, what your bike's factory chart calls for: main jet, needle and clip, pilot jet and air screw. • AFR against throttle chart with every setup on it, and the comparison with the reference over low, mid and high throttle. • As many setups as you like, with name, colour, notes and date. TRACK MODE, WIDGETS AND APPLE WATCH • Track mode: what the chart calls for, large and high-contrast, with what is fitted underneath if it differs, the air density and how old the data is. Readable in full sun, helmet on. • Race day: for 12 hours on the lock screen, in the Dynamic Island and on the watch. • Home and lock screen widgets, and an Apple Watch app with complications. ALERTS, FORECAST AND ICING • During the race day, if the air density changes enough to change the main jet, you get an alert, also from the Apple Weather hourly forecast. • Carburettor icing warning from temperature and humidity. FUEL 98 E5, E10, E15, E0, leaded race fuel, E10 race fuel, oxygenated or your own ethanol percentage. The factory jetting and the chart are corrected with its stoichiometric ratio. Octane does not change the jetting; ethanol does. THE WHOLE CARBURETTOR • Main and pilot jet, needle and clip, air screw and slide cutaway. • Family and bore: PWK from 21 to 42 mm, PWM 36 and 38, PJ from 34 to 38. • Fuel density and oil mix, with a fuel mix calculator. NEEDLES • Keihin needle catalogue with its geometry, in both series: the one for PWK 33-39, PWM and PJ, and the short one for 26 to 28 mm. • Search by code or by bike, and compare two needles on one chart. WEATHER Temperature, humidity, pressure and altitude, by hand or from the nearest station, with air density, density altitude and dew point. Metric or imperial units. ICLOUD AND SHARING • Your setups and settings on all your iPhones and iPads through your iCloud. • Link, file or QR code for your mechanic: it opens in the app if they have it, or in the browser. ALSO • Dark mode. Help on every screen. • In English, Spanish, French, Italian, German and Portuguese. iPhone and iPad. The model is empirical and meant for comparing setups. It is no substitute for track testing or for reading the spark plug. An independent app, not affiliated with Keihin or Hitachi Astemo. Brand and model names are used only to identify parts and engines.