MerCruiser Cooling System
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OEM Quicksilver/Mercury Small Block 5.0 5.7 6.2 350 377 Circulating Pump 46-8M0113734
Mercury Marine / Quicksilver
$166.58 $142.99OEM Quicksilver/Mercury Small Block Circulating Pump 46-8M0113734 Replacement water pump with housing 8M0113734 is for V-6 (serial number 1A603239 and below) and V-8 (305, 350 and 377 cid) MerCruiser engines made by General Motors. See your owner's...- Part Number:
- 710-46-8M0113734
- Availability:
- In Stock - Ships same or next business day.
- Application:
- GM V-6(s/n 1A063239 & below) & V-8 (350 & 377 cid) engines
$166.58 $142.99 -
OEM MerCruiser 4.3/5.0/5.7 V6/V8 Brass Sea Water Pump 862914T3 862914T10 8M0118067 8M0137216 8M0122655 8M0139995
Mercury Marine / Quicksilver
$601.42 $533.46NEW OEM Factory MerCruiser BRASS sea water pump assy WITHOUT Air Fittings (AKA Raw Water Pump/ Seawater pump) Casting number on this pump housing is 8629140 and the casting number on the back nipple plate is 862776c and is removable if yours...- Part Number:
- 710-46-8M0139995
- Availability:
- In Stock - Ships same or next business day.
$601.42 $533.46 -
OEM MerCruiser Thermostat Housing Gasket 27-530451
Mercury Marine / Quicksilver
$5.50 $3.22MerCruiser Thermostat Housing Gasket 27-530451 Thermostat Housing Gasket 530451 is for use on V-6 and V-8 MerCruiser stern drive and inboard engines made by General Motors. It can also be used on Outboard Marine Corporation and Volvo Penta North America...- Part Number:
- 710-27-53045 1
- Availability:
- In Stock - Ships same or next business day.
- Description:
- T-Stat housing gasket w/grounding tabs Repl OEM No. Marine Pwr# 0505-027 MC# 3852111 Volvo# 3852111-8
$5.50 $3.22 -
OEM MerCruiser Blue Plastic Drain and O-Ring 806608A02 22-806608Q01
Mercury Marine / Quicksilver
$9.50 $5.56MerCruiser Blue Plastic Drain and O-Ring 22-806608Q01 806608A02 The Quicksilver plastic blue Drain Plug Kit fits MerCruiser cylinder blocks and exhaust manifolds- Part Number:
- 710-22-806608Q01
- Availability:
- In Stock - Ships same or next business day.
$9.50 $5.56 -
OEM Mercury MerCruiser Water Pump Drive Shaft Kit 8M0140001
Mercury Marine / Quicksilver
$122.67 $86.11Mercury / Quicksilver IMPLLR DRVSHFT KT 8M0140001- Part Number:
- 710-8M0140001
- Availability:
- In Stock - Ships same or next business day.
$122.67 $86.11 -
OEM Quicksilver/Mercury Thermostat-160 Degree 8M0109441
Mercury Marine / Quicksilver
$33.00 $28.49Thermostat 8M0109441: Is for MerCruiser engines made by General Motors with standard cooling systems requiring the use of the 160 degree (F) thermostat. Easy to replace with common tools. See your owner's manual for removal of non-functioning...- Part Number:
- 710-8M0109441
- Availability:
- In Stock - Ships same or next business day.
- Temp.:
- 160 Deg -
- Application:
- 1987 & newer GM engines w/standard cooling requiring 160 Deg - thermostat
$33.00 $28.49 -
OEM Quicksilver/Mercury Thermostat Kit- 160 Degree 807252Q 5
Mercury Marine / Quicksilver
$44.92 $38.49OEM Quicksilver/Mercury Thermostat Kit- 160 Degree 807252Q 5 Thermostat 807252Q5 is for V-6 and V-8 MerCruiser engines (except high performance engines) made by General Motors (model year 1987 through 2016) with standard cooling requiring a 160...- Part Number:
- 710-807252Q 5
- Availability:
- In Stock - Ships same or next business day.
- Description:
- GM engines '87 & later w/ Std. Cooling requiring a 160 Deg - thermostat
$44.92 $38.49 -
OEM MerCruiser Sea Water Pump Assembly -With Serpentine Pulley 46-807151A9
Mercury Marine / Quicksilver
$570.79Replacement sea water pump housing 807151A9 is plastic to combat corrosion in saltwater installations. It is for V-6 and V-8 MerCruiser engines made by General Motors with a serpentine belt pulley system for engine accessories and electrical fuel pumps...- Part Number:
- 710-46-807151A 9
- Availability:
- In Stock - Ships same or next business day.
$570.79 -
OEM Quicksilver/Mercury Big Block 454 502 7.4 Circulating Pump 46-8M0113735
Mercury Marine / Quicksilver
$266.58 $228.49OEM Quicksilver/Mercury Big Block Circulating Pump 46-8M0113735 Replacement bi-directional water pump with housing 8M0113735 is for V-8 (454 and 502 cid) MerCruiser engines made by General Motors. See your owner's manual or service manual for...- Part Number:
- 710-46-8M0113735
- Availability:
- In Stock - Ships same or next business day.
- Application:
- GM V-8 (454 & 502 cid) engines
$266.58 $228.49 -
OEM Quicksilver/Mercury 4-Cycle In-Line Circulating Pump 46-8M0113733
Mercury Marine / Quicksilver
$149.92 $118.11OEM Quicksilver/Mercury 4-Cycle In-Line Circulating Pump 46-8M0113733 Please confirm fitment of MerCruiser parts with your serial numberPhotos and descriptions provided via Mercury may not always be accurateAll of our Mercury parts are sold and priced...- Part Number:
- 710-46-8M0113733
- Availability:
- In Stock - Ships same or next business day.
- Application:
- GM 4 cyl. & in-line 6 cyl.
$149.92 $118.11 -
OEM MerCruiser Bravo V8 454/502 Sea Water Pump With Pulley 46-807151A8
Mercury Marine / Quicksilver
$993.64 $993.49OEM MerCruiser Bravo V8 454/502 Sea Water Pump With Pulley 46-807151A8 (AKA Raw Water Pump/ Seawater pump) Pulley includedFits 454 502 1992 - 1999 with the mount for the fuel pumpAlternate 46-807151a 8 Replacement sea water pump housing 807151A8 is...- Part Number:
- 710-46-807151A 8
- Availability:
- In Stock - Ships same or next business day.
$993.64 $993.49 -
OEM MerCruiser Sea Water Pump Assembly V-Belt 46-807151a12
Mercury Marine / Quicksilver
$573.24 $473.32MerCruiser sea water pump assembly (AKA Raw Water Pump/ Seawater pump) Pulley not included Replacement sea water pump housing 807151A12 is plastic to combat corrosion in saltwater installations. It is for V-6 and V-8 MerCruiser engines made by...- Part Number:
- 710-46-807151A12
- Availability:
- In Stock - Ships same or next business day.
$573.24 $473.32 -
OEM MerCruiser Therm Cover Gasket Lower 27-53045Q01
Mercury Marine / Quicksilver
$5.50 $3.22OEM MerCruiser Therm Cover Gasket Lower 27-53045Q01 The Quicksilver Thermostat Housing Gasket fits MCM/MIE GM V‑8 engines.- Part Number:
- 710-27-53045Q01
- Availability:
- In Stock - Ships same or next business day.
- Description:
- Thermostat housing gasket w/grounding tabs. For MerCruiser GM V-6 & V-8 engines.
$5.50 $3.22 -
OEM Quicksilver/Mercury Thermostat 140 Degree 8M0089715
Mercury Marine / Quicksilver
$26.58 $22.99OEM Quicksilver/Mercury Thermostat 140 Degree 8M0089715 Thermostat 8M0089715 is for various MerCruiser stern drive applications with standard cooling systems. See your owner's manual or service manual for specific applications and installation...- Part Number:
- 710-8M0089715
- Availability:
- In Stock - Ships same or next business day.
- Temp.:
- 140 Deg -
- Application:
- MerCruiser GM Engines
$26.58 $22.99 -
OEM MerCruiser 496 Brass Sea Water Pump With Air Fittings 46-862914T12 46-8M0122658 46-8M0139997
Mercury Marine / Quicksilver
$1,178.79 $982.98OEM MerCruiser 496 Brass Sea Water Pump With Air Fittings 46-862914T12 46-8M0122658 New Number 46-8M0139997 Pulley Not IncludedOld Part number 46-862914T12 superseded to new Part Number: 46-8M0122658 Superseded again to 46-8M0139997 Please...- Part Number:
- 710-46-8M0139997
- Availability:
- In Stock - Ships same or next business day.
$1,178.79 $982.98 -
OEM Quicksilver/Mercury Thermostat Kit- 140 Degree 807252Q 4
Mercury Marine / Quicksilver
$55.00 $46.99OEM Quicksilver/Mercury Thermostat Kit- 140 Degree 807252Q 4 Thermostat 807252Q4 is for V-6 and V-8 MerCruiser engines (except high performance engines) made by General Motors (model year 1983 through 2016) with standard cooling requiring a 140...- Part Number:
- 710-807252Q 4
- Availability:
- In Stock - Ships same or next business day.
- Description:
- GM V-6/V-8 1983 & later w/ Std. Cooling except Hi-Performance models: 140 Deg -
$55.00 $46.99 -
OEM Mercury / Quicksilver 496 Sea Water Pump w/o Air Fittings 46-8M0139994
Mercury Marine / Quicksilver
$822.21 $686.26Mercury / Quicksilver SEA PUMP KIT 46-8M0139994- Part Number:
- 710-46-8M0139994
- Availability:
- In Stock - Ships same or next business day.
$822.21 $686.26 -
OEM MerCruiser V6/V8 Brass Sea Water Pump With Air Fittings 862914T11 8M0122657 8M0139996
Mercury Marine / Quicksilver
$1,031.36 $862.23OEM MerCruiser V6/V8 Brass Sea Water Pump With Air Fittings 46-862914T11 46-8M0122657 Item Supersession Chain: RowClassPart NumberSS LevelDispDescription 1 46 8M0139996 00 ACT SEA PUMP KIT 2 46 8M0137217 01 SS SEA PUMP KIT 3 46 8M0122657 02...- Part Number:
- 710-46-8M0139996
- Availability:
- In Stock - Ships same or next business day.
$1,031.36 $862.23 -
OEM MerCruiser Seawater Pump Backing plate for pump 8M0139995 8M0180871
Mercury Marine / Quicksilver
$9.99OEM MerCruiser Seawater Pump Backing plate for pump 8M0139995 8M0180871- Part Number:
- 710-8M0180871
- Availability:
- In Stock - Ships same or next business day.
$9.99 -
OEM MerCruiser Thermostat Gasket 27-47510
Mercury Marine / Quicksilver
$3.30 $1.93MerCruiser Thermostat Gasket 27-47510 The Quicksilver Thermosat Gasket fits MCM/MIE GM V-6 & V-8 engines w/older style 2 piece thermostat housing.- Part Number:
- 710-27-47510
- Availability:
- In Stock - Ships same or next business day.
- Description:
- T-Stat Gasket: GM V-6 & V-8 engines w/older style 2-pc thermostat housing.
$3.30 $1.93
Cooling System
The Mercruiser cooling system works by circulating cold water around the engine block to cool your MerCruiser engine parts. There are two types of cooling systems; raw water cooling and closed cooling systems. The MerCruiser raw water cooling system functions by drawing water from the lake or sea and carrying it through the engine block to the exhaust system. A closed cooling system employs a heat exchanger, which uses raw seawater to cool hot distilled water. The cooled distilled water runs through the engine block and cools the engine instead of the raw seawater.
The closed cooling system is kinder to the water distribution system than the the raw water cooling system because it is less prone to rusting. A raw water cooling system has a shorter lifespan than a closed cooling system. A fresh water cooling system Mercruiser allows your engine to run at higher temperatures, resulting in a better functioning fuel system.
7.4 Mercruiser cooling system
The thermostat is a small but essential cooling system component that is often overlooked. The thermostat valve regulates the engine's temperature by closing or opening its valve. The valve closes to increase engine temperature by preventing cooling water from passing through the engine block. Once the temperature is high enough, the valve opens to allow cooling water to pass around the heat exchanger and circulating pump to cool the engine. You can refer to the 7.4 Mercruiser cooling system diagram to better understand how the entire system works.
PowerBoatSupply.com recommends regular inspection of your cooling system, from the seawater strainer, raw water pump, heat exchanger hoes, and thermostat housing to the circulating water pump. A faulty thermostat will either fail to open or close. If the thermostat valve remains closed, the engine will overheat and cause damage to the ignition system. We recommend replacing the thermostat every two years and installing an electric overheat horn to prevent overheating damages.
Cooling System Replacement Parts You Can Depend On
PowerBoatSupply.com has provided boat owners and marine mechanics with quality OEM and aftermarket replacement parts for four decades. We believe in investing in premium replacement parts like exhaust manifold kits, serpentine belts, and circulating pumps for peak marine engine performance.
Contact us today and our experienced team of marine mechanics will help you find the right replacement parts for your boat's engine.