Quicksilver 8M0228409 - Thermostat for Mercury 2.5-6hp carbureted outboardsThermostat 8M0228409 is for Mercury 2.5-6hp carbureted engines. It is a 120F thermostat. Thermostat only. Additional seals or gaskets may be required. See your owner's manual or service manual for more information.Key Product Features Thermostat for select Mercury 2.5-6hp carbureted engines; Corrosion resistant stainless steel delivers increased service life; Self-cleaning design allows cooling system contaminants to flush through closing surfaces; Calibrated for proper cooling system temperature response; Easy to replace with common tools; See your owner's manual for removal of non-functioning thermostat and replacement of new thermostat; Application Information:Fits 2/2.5/3.5hp (0R131842-0R504789), 4/5/6hp (0R000001 and above) FourStroke outboards.