JETTING

Last month I skimmed over the jetting, and ended up receiving a few questions on the matter, so here’s a bit more in-depth info: This is a 2015 catalysed PX125, due to the cat exhaust and other Euro 3 emission friendly restrictions it runs this jetting as standard: Si 20/20 carb with 140 air corrector – BE5 atomiser – 96 main, and a 45/145 pilot. When fitting the SIP Road 2.0 exhaust, I changed the air corrector to a 120 and the pilot jet to a 50/100. All else remained the same. This did give ever so slightly rich readings, especially lower down the rev-range, but that’s how I like to run things… nice n’ safe. The net result is, that it’s lovely and rich when cruising at full revs, and still nice and safe when you throttle off. Plus, if/when the additional running modifications in this article are carried out, still no further jetting changes were required! The air/fuel reading reads perfect, and the throttle can be held wide open, at peak rpm for miles. Back-up plug chops show a nice dark plug. For the paranoid and eternal doubters, feel free to fit a 98 main.