MerCruiser Cooling System
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OEM Quicksilver/Mercury Thermostat 864493
Mercury Marine / Quicksilver
$32.49 $25.06OEM Quicksilver/Mercury Thermostat 864493 Thermostat 864493 is for MerCruiser stern drive engines 4.3L, 4.5L, 5.0L, 5.7L and 6.2L MPI (Multi-Port Injection) with dry joint exhaust and closed cooling systems. It is a 170 F degree thermostat.- Part Number:
- 710-864493
- Availability:
- In Stock - Ships same or next business day.
- Temp.:
- 170 Deg -
- Application:
- MCM 4.3L - 5.0L - 5.7L & 6.2L MPI engines with dry joint exhaust and closed cooling
$32.49 $25.06 -
OEM MerCruiser ExhaustManifold Drain Plug 22-16951Q 1
Mercury Marine / Quicksilver
$30.49 $23.55MerCruiser ExhaustManifold Drain Plug 22-16951Q 1 Engine block or manifold drain plug 16951A1 fits most MerCruiser stern drive or inboard engines blocks and manifolds to make draining cooling water for winterizing or changing anti-freeze easier. Can be...- Part Number:
- 710-22-16951Q 1
- Availability:
- In Stock - Ships same or next business day.
- Replaces:
- OMC 379957 - Volvo 82745-1
$30.49 $23.55 -
OEM Quicksilver/Mercury Thermostat Kit- 140 Degree 807252Q 3
Mercury Marine / Quicksilver
$34.99 $29.99OEM Quicksilver/Mercury Thermostat Kit- 140 Degree 807252Q 3 Thermostat Kit 807252Q3 is for 1982 and older, V-8 MerCruiser marinized stern drive and inboard engines with standard cooling systems made by Ford Motor Company or General Motors. It is...- Part Number:
- 710-807252Q 3
- Availability:
- In Stock - Ships same or next business day.
- Description:
- GM & Ford V-8's 1982 & older w/ Std. Cooling/Hi-Performance V-8's 1996 & older & closed cooling: 140 Deg -
$34.99 $29.99 -
OEM Quicksilver/Mercury Water Pump Impeller Kit 47-59362A 4
Mercury Marine / Quicksilver
$61.49 $45.92OEM Quicksilver/Mercury Water Pump Impeller Kit 47-59362A 4 This five-piece kit contains the impeller, face plates and o-ring to replace those parts in MerCruiser Bravo I, II and III drives.- Part Number:
- 710-47-59362A 4
- Availability:
- In Stock - Ships same or next business day.
- Type:
- Impeller Kit
- Application:
- Fits plastic 2 piece body sea water pump
$61.49 $45.92 -
OEM Quicksilver/Mercury Thermostat 130 Degree 8M0057307
Mercury Marine / Quicksilver
$129.49 $110.99OEM Quicksilver/Mercury Thermostat 130 Degree 8M0057307 Thermostat 8M0057307 is for select Mercury Optimax, 3.0L, non-Pro, V-6 outboards (s/n 1B227000 and above). It is a 130 F degree thermostat. Thermostat only. Additional seals or gaskets may be...- Part Number:
- 710-8M0057307
- Availability:
- In Stock - Ships same or next business day.
- Temp.:
- 130 Deg -
- Application:
- 3.0L OptiMax
$129.49 $110.99 -
OEM Quicksilver/Mercury Thermostat Kit- 160 99155T 1
Mercury Marine / Quicksilver
$40.49 $30.66OEM Quicksilver/Mercury Thermostat Kit- 160 99155T 1 Thermostat 991551T1 is L98for 1998 and newer MerCruiser marinized V-6 and V-8 engines made by General Motors using closed cooling systems and requiring the use of the 160 F degree thermostat. It is a...- Part Number:
- 710-99155T 1
- Availability:
- In Stock - Ships same or next business day.
- Description:
- GM V-6/V-8 1998 & later w/ closed cooling
$40.49 $30.66 -
OEM Quicksilver/Mercury Thermostat- 160 99155 1
Mercury Marine / Quicksilver
$39.99 $30.07OEM Quicksilver/Mercury Thermostat- 160 99155 1 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 EACH- Part Number:
- 710-99155 1
- Availability:
- In Stock - Ships same or next business day.
- Temp.:
- 160 Deg -
- Application:
- 1998 and newer GM V-6 & V-8 engines with closed cooling
$39.99 $30.07 -
OEM Quicksilver/Mercury O/B Thermostat Kit 75692Q 2
Mercury Marine / Quicksilver
$53.99 $45.99OEM Quicksilver/Mercury O/B Thermostat Kit 75692Q 2 Thermostat 75692Q2 is for 135 hp through 15 hp V-6 Mercury and Mariner outboards with serial number A9046446 and higher; 175 hp Mercury and Mariner V-6 outboards with serial numbers C100861 and...- Part Number:
- 710-75692Q 2
- Availability:
- In Stock - Ships same or next business day.
- Description:
- Kit incl. 2 ea.: Thermostat & Gasket V-6 135-150hp S/N A904646 & later - V-6 175hp S/N C100861 & later - V-6 200hp S/N 6435503 & later
$53.99 $45.99 -
OEM MerCruiser Thermostat Housing Gasket 27-33179Q02
Mercury Marine / Quicksilver
$4.89 $4.49OEM MerCruiser Thermostat Housing Gasket 27-33179Q02 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 EACH- Part Number:
- 710-27-33179Q02
- Availability:
- In Stock - Ships same or next business day.
- Application:
- MCM/MIE GM 4 cyl. - V-6 & V-8 engines - for thermostat housing with flat cover plate
$4.89 $4.49 -
OEM Quicksilver/Mercury Thermostat Kit- 140 Degree 59078Q 3
Mercury Marine / Quicksilver
$36.49 $31.49OEM Quicksilver/Mercury Thermostat Kit- 140 Degree 59078Q 3 Thermostat 59078Q3 kit is for use in older MerCruiser in-line 4-cylinder and 6-cylinder engines made by General Motors. The two-piece kit includes the thermostat and cork gasket.- Part Number:
- 710-59078Q 3
- Availability:
- In Stock - Ships same or next business day.
- Description:
- GM In-line 4 & 6 cylinder: 140 Deg -
$36.49 $31.49 -
OEM MerCruiser V8 Sea Water Pump Assembly V-Belt 46-72774A32
Mercury Marine / Quicksilver
$718.93 $609.16OEM MerCruiser V8 Sea Water Pump Assembly V-Belt 46-72774A32 (AKA Raw Water Pump/Seawater pump) • Pulley not included • Fits most V8 MerCruiser engines from 1985-1995 Replacement water pump housing 72774A32 is brass to combat...- Part Number:
- 710-46-72774A32
- Availability:
- In Stock - Ships same or next business day.
$718.93 $609.16 -
OEM Quicksilver/Mercury Thermostat- 140 Degree 59078
Mercury Marine / Quicksilver
$37.99 $28.74OEM Quicksilver/Mercury Thermostat- 140 Mercury 59078 Thermostat 59078 is for use in MerCruiser 120/2.5L engines (with s/n 2324347 and higher) with cast iron exhaust manifolds. Also for use in MerCruiser 140/3.0L engines (with s/n 0L340999 and below) and...- Part Number:
- 710-59078
- Availability:
- In Stock - Ships same or next business day.
- Temp.:
- 140 Deg -
- Application:
- MCM GM in-line 4 & 6 cyl. engines
$37.99 $28.74 -
OEM MerCruiser Thermostat- 120 Degree 14586
Mercury Marine / Quicksilver
$39.49 $33.49MerCruiser Thermostat- 120 Degree 14586 Thermostat 14586 is for Mercury 40 hp through 60 hp 4-stroke outboards (s/n 1C050252 and above). It is a 120 F degree thermostat. Thermostat only. Additional seals or gaskets may be required. See your owner's...- Part Number:
- 710-14586
- Availability:
- In Stock - Ships same or next business day.
- Description:
- 120¼
$39.49 $33.49 -
OEM Quicksilver/Mercury O/B Thermostat- 143 Degree 833072003
Mercury Marine / Quicksilver
$50.49 $42.99OEM Quicksilver/Mercury O/B Thermostat- 143 Degree 833072003 Thermostat 833072003 is for select Mercury Optimax, 2.5L, non-Pro, V-6 outboards (s/n 1B227000 and above). It is a 143 F degree thermostat. Thermostat only. Additional seals or gaskets...- Part Number:
- 710-833072003
- Availability:
- In Stock - Ships same or next business day.
- Temp.:
- 143 Deg -
- Application:
- Optimax Mercury O/B with 2.5L - 135-200 hp
$50.49 $42.99 -
OEM Quicksilver/Mercury Thermostat 75692Q03
Mercury Marine / Quicksilver
$28.49 $24.49OEM Quicksilver/Mercury Thermostat 75692Q03 Quicksilver thermostat Kit 143 Degrees fits Mercury/Mariner V-6 135 hp, V-6 150 hp A904646>, V-6 175 hp C100861>, and V-6 200 hp 6435503>. Replaces Evinrude and Johnson OMC #434841. Fits 5 - 55 hp...- Part Number:
- 710-75692Q03
- Availability:
- In Stock - Ships same or next business day.
$28.49 $24.49 -
OEM Quicksilver/Mercury 143 3-Cycle/V6 O/B Thermostat 75692
Mercury Marine / Quicksilver
$24.99 $21.49OEM Quicksilver/Mercury 143 3-Cycle/V6 O/B Thermostat 75692 Thermostat 75692 is for select 135 hp through 200hp Mercury and Mariner EFI and carburetor fueled 2-cycle, V-6 outboards. It is a 143 F degree thermostat. Thermostat only. Additional seals...- Part Number:
- 710-75692
- Availability:
- In Stock - Ships same or next business day.
- Description:
- Thermostat - 143¼
$24.99 $21.49 -
Sold Out, please call for ETA.
OEM MerCruiser Thermostat Housing Gasket 27-47590Q01
Mercury Marine / Quicksilver
$2.35MerCruiser Thermostat Housing Gasket 27-47590Q01 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:
- 710-27-47590Q01
- Availability:
- In Stock - Ships same or next business day.
- Application:
- Renault 90 & GM in-line 4 & 6 cyl. Engines
$2.35 -
OPEN BOX OEM Mercury / Quicksilver 496 Sea Water Pump w/o Air Fittings 46-8M0139994
Mercury Marine / Quicksilver
$822.21 $599.99OPEN BOX OEM Mercury / Quicksilver SEA PUMP KIT 46-8M0139994- Part Number:
- OPENBOX-46-8M0139994
- Availability:
- In Stock - Ships same or next business day.
$822.21 $599.99
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.