MCS Jets Keihin

32 products in Jets

Keihin jets from MCS cover the main and slow jet sizes required when rejetting a Keihin CV or butterfly carburettor on a Harley-Davidson Evolution or Sportster model after fitting a performance exhaust, air cleaner, or both. The factory jet specification in a Keihin-carbureted Harley-Davidson is calibrated for emissions compliance rather than optimal performance — changing the air cleaner and exhaust alters the fuelling requirement, and the correct response is to rejet rather than accept the lean running condition that results from more airflow with unchanged fuel delivery. MCS stocks a range of main jet and slow jet sizes to allow builders to dial in the correct mixture for their specific Harley-Davidson configuration. Iron City Motorcycles in Leeds stocks Keihin jets alongside carburettor rebuild kits, air cleaners, and the other components needed to support a carburettor refresh or performance tune on carbureted Harley-Davidson models. Browse the full MCS Jets Keihin range below.