carburetor main jet 101 OCTANE Gurtner 050

Gurtner main jet size 50. With the E2 standard and other performance-restricting measures, the jets are too small. Recommended when fitting a sports exhaust or a 70cc cylinder. An increase of 10–15% is recommended for systems or 70cc cylinders. Check the spark plug to see how the mixture is running: light brown – optimal, black – too rich (jet too large), grey to whitish – too lean (jet too small) and there is a danger of seizure.