MCS Breather Valves Spacers

21 products — part of all Breather Valves Spacers

MCS breather valve spacers give Harley-Davidson mechanics and builders the correct clearance components for crankcase breather assemblies on Big Twin and Sportster engines. The breather system vents crankcase pressure that builds as the pistons pump up and down — incorrect spacer fitment affects the seal between the breather body and the rocker cover or air cleaner backing plate, leading to oil mist ingestion into the intake and rough running. MCS produce their breather spacers to Harley-Davidson specifications covering the main engine families and breather configurations used across Evo, Twin Cam and Sportster designs. Having the correct spacer thickness ensures the breather valve operates in the correct position for reliable crankcase venting without oil carry-over. Iron City Motorcycles, Leeds' authorised Harley-Davidson dealer, carries MCS breather components alongside a comprehensive engine and air intake parts range. Browse the full MCS Breather Valves Spacers range below.