Water is inducted through the lower unit by a water pump impeller in the cooling system on an outboard and then forced upward to circulate throughout the powerhead, and eventually exits through the exhaust system.
Flush-M
Flush-M - Mercury Outboard Flushing Solution - Black - 75-450HP Models
$75.00Unit price /UnavailableMercury
Mercury 3.4L V6 - 4.6L V8 Water Pump Repair Kit - 98-8M0142980
$47.50$55.92Unit price /UnavailableMercury
Mercury - Complete Water Pump - Fits 30-60 HP EFI & Carbureted FourStroke - 46-812966A12
$149.99$174.83Unit price /UnavailableMercury
Mercury - Poppet Valve Kit - Fits V-6 Outboard Models - 803062T1
$32.63$38.42Unit price /UnavailableMercury
Mercury - Complete Outboard Water Pump Kit - Fits 40-125 HP - 46-8M0113799
$171.49$199.92Unit price /UnavailableMercury
Mercury 853792A07 Outboard Water Pump Repair Kit - Fits 25-30 HP EFI Four Stroke
$76.09$89.58Unit price /UnavailableMercury
Mercury - Outboard Water Pump Impeller - Fits Various Outboards 3.9-9.8 HP - 47-89981
$22.99$26.58Unit price /UnavailableMercury
Mercury - Water Impeller Repair Kit - Fits 40-45-50 HP Four Stroke - 821354A2
$58.49$68.33Unit price /UnavailableMercury
Mercury 47-803748K01 Outboard Water Impeller Repair Kit - Fits 8/9.9 HP Four Stroke
$70.99$86.22Unit price /UnavailableMercury
Mercury 8M0117413 Outboard Thermostat - Fits 40-60 HP SeaPro EFI Four Stroke
$29.09$34.25Unit price /UnavailableMercury
Mercury - Outboard Water Pump Impeller - Fits Various 30-60 HP Four Stroke - 47-19453T
$45.99$53.58Unit price /UnavailableMercury
Mercury - Outboard Water Pump Impeller - Fits 9.9 HP Four Stroke MY 2005 - 47-803748
$27.53$32.42Unit price /UnavailableMercury
Mercury - Water Pump Impeller - Fits Various 15-25 HP - 47-8508910
$31.92$37.58Unit price /UnavailableMercury
$114.60$134.92Unit price /UnavailableMercury
Mercury - Outboard Water Temperature Sender - Fits V-6 Outboards - 13536A14
$51.25$60.33Unit price /UnavailableMercury
Mercury - Outboard Water Temperature Sender - Fits V-6 outboard - 13536A13
$39.99$47.08Unit price /UnavailableMercury
Mercury - Outboard Complete Water Pump - Fits 30-60 HP - 46-8M0113801
$174.37$206.58Unit price /UnavailableMercury
$27.75$32.88Unit price /UnavailableMercury
Mercury 47-803748K02 Outboard Water Impeller Repair Kit - Fits 9.9 HP Four Stroke
$73.49$91.91Unit price /UnavailableFlush-M
Flush-M - Suzuki Outboard Flushing Solution - Black - DF25 to DF350HP Models
$75.00Unit price /UnavailableMercury
$22.99$26.58Unit price /UnavailableMercury
Mercury - Outboard Water Pump Upper Housing - 817275A1
$83.81$98.67Unit price /UnavailableMercury
Mercury - Sea Water Pump - Fits MCM/MIE 4.3L, 5.0L, 5.7L & 6.2L MPI w/ ECM 555 - 46-8M0139995
$615.45Unit price /UnavailableMercury
Mercury - Outboard Water Pump Impeller - Fits MCM & Outboard Applications - 47-89984T4
$40.99$47.58Unit price /UnavailableMercury
$13.52$19.10Unit price /UnavailableMercury
$106.49$124.50Unit price /UnavailableMercury
Mercury - Outboard Complete Water Pump - Fits 3.0L DFI - 817275A5
$133.49$155.75Unit price /UnavailableMercury
Mercury - Water Circulating Pump - Fits GM V‑6 & V‑8 Engines - 46-8M0113734
$142.99$166.58Unit price /UnavailableMercury
$22.93$27.00Unit price /UnavailableMercury
Mercury 47-19453T2 Outboard Water Impeller Repair Kit - Fits 50 - 55 - 60 HP 3 Cylinder - 2-cycle
$86.99$103.54Unit price /Unavailable
Most newer Mercury Marine outboard engines use an enclosed cooling system. This means that there is a small tank on the top of the engine that uses a combination of fresh water and coolant.
This fresh water is circulated through the engine and through a heat exchanger. The fresh water, in this system, absorbs the heat of the engine. Mercury outboard motors are typically designed as open loop cooling systems. Meaning the motor draws water from the host body. That water is circulated through the engine, and fuel pump to maintain prop engine temperatures. After passing through the engine or fuel pump the water is then dumped back into the host body. Water is drawn into the water pump through the intake opening of the lower unit, where it passes through a cavity that ends up entering the pump itself. At that point, the impeller pressures the water into the long inlet tube leading to the bottom side of the powerhead. Internal combustion engine cooling uses either air or liquid to remove the waste heat from an internal combustion engine. For small or special-purpose engines, cooling using air from the atmosphere makes for a lightweight and relatively simple system. Cooling system, apparatus employed to keep the temperature of a structure or device from exceeding limits imposed by needs of safety and efficiency.