EMP 75-75517 Thermostats & Parts Four-stroke outboards run differently than two-strokes, and their cooling systems reflect that. Mercury and Mariner 4-stroke outboards in the 65 to 115 horsepower range are designed to operate at higher internal temperatures than their two-stroke counterparts, which is why the thermostat in these engines opens at 120 degrees Celsius (248 degrees Fahrenheit) rather than the lower ratings you will find on two-stroke applications. That higher operating temperature is intentional. It supports more complete combustion, better fuel efficiency, and lower emissions, all of which are part of what makes modern 4-stroke outboards as clean and efficient as they are. Using a thermostat with the wrong opening temperature on one of these engines will push it outside its designed operating range and undermine those advantages. The EMP 75-75517 Thermostat fits Mercury and Mariner 4-stroke outboards across the 65, 75, 80, 90, 100, and 115 horsepower ratings. It is a direct replacement for Mercury and Mercruiser part number 8M0090819 and Sierra part number 18-3633. If you are cross-referencing from either of those numbers, you are in the right place. EMP manufactures this thermostat to OEM specifications, so the opening temperature, flow characteristics, and physical dimensions match the original exactly. Thermostat replacement is a straightforward service item that is easy to include in a seasonal tune-up or any time the cooling system is opened for inspection. On a 4-stroke outboard that sees regular use, staying ahead of thermostat maintenance is a simple way to protect the engine and keep it running at the efficiency it was designed for. Compatibility and specs at a glance: Fits Mercury and Mariner 4-stroke outboards, 65, 75, 80, 90, 100, and 115 horsepower Opens at 120 degrees Celsius (248 degrees Fahrenheit) Designed specifically for 4-stroke applications Replaces Mercury and Mercruiser 8M0090819 Replaces Sierra 18-3633 Built to OEM specifications by EMP Direct replacement, no modification required for listed applications Normalized SKU: 7575517UPC Code: 840080496382

EMP 75-75516 Thermostats & PartsEMP Thermostat #75-75516Normalized SKU: 7575516UPC Code: 840080496375

EMP 75-75515 Thermostats & PartsEMP Thermostat #75-75515Normalized SKU: 7575515UPC Code: 840080496368

EMP 75-75514 Thermostats & PartsEMP Thermostat #75-75514Normalized SKU: 7575514UPC Code: 840080496351

EMP 75-75513 Thermostats & PartsEMP Thermostat #75-75513Normalized SKU: 7575513UPC Code: 840080496344

EMP 75-75508 Thermostats & PartsEMP Thermostat #75-75508Normalized SKU: 7575508UPC Code: 840080499604

EMP 75-75507 Thermostats & PartsThis product replaces:840080424101Normalized SKU: 7575507UPC Code: 840080424101

EMP 75-75500 Thermostats & Parts This thermostat fits Yamaha 115 HP and 200-350 HP outboards from 2003 and later, covering both 2-stroke and 4-stroke configurations. It replaces two Yamaha OEM part numbers, 60V-12411-00-00 and 68V-12411-00-00, and installs as a direct fit with no modifications needed. The thermostat regulates coolant flow through the powerhead, holding water back until the engine reaches operating temperature and then opening to allow circulation. A stuck-closed thermostat causes overheating; a stuck-open one means the engine never fully warms up and runs less efficiently. If your Yamaha is running outside its normal temperature range, the thermostat is one of the first things worth checking. Compatible Applications: Yamaha 115 HP, 2-stroke and 4-stroke (2003 and later) Yamaha 200-350 HP, 2-stroke and 4-stroke (2003 and later) Replaces OEM Part Numbers: Yamaha 60V-12411-00-00, 68V-12411-00-00 Also Crosses With: Sierra: 18-3525 Normalized SKU: 7575500UPC Code: 840080447346

EMP 75-75100 Thermostats & Parts The thermostat is one of those components that works quietly in the background until it does not, and when it fails, the engine tends to make its displeasure known fairly quickly. On a Yamaha outboard, the thermostat regulates coolant flow to keep the engine operating within its designed temperature range. A thermostat that sticks open causes the engine to run too cold, which leads to incomplete combustion, plug fouling, and increased wear over time. One that sticks closed is the more urgent problem, as coolant flow stops and engine temperatures climb toward the overheat alarm in short order. The EMP 75-75100 is a 50-degree Celsius thermostat, meaning it begins to open at 50 degrees C (122 degrees F) and allows coolant to flow once the engine reaches that temperature. This is the correct opening temperature for the listed Yamaha applications, so if you are replacing a thermostat on one of these engines, this is the spec you want. Using a thermostat with the wrong opening temperature will cause the engine to run outside its intended operating range, which affects both performance and longevity. This thermostat fits a broad range of Yamaha outboards, from smaller 9.9 to 25 horsepower engines all the way up to 150 to 250 horsepower models, with 30 to 90 horsepower and 115 to 130 horsepower applications covered in between. It is a direct replacement for five Yamaha part numbers: 6E5-12411-30-00, 688-12411-11-00, 688-12411-10-00, 688-12411-01-00, and 688-12411-00-00. If you are cross-referencing from any of those numbers, you are in the right place. EMP manufactures this thermostat to OEM specifications for proper fit and accurate temperature response. Compatibility and specs at a glance: Fits Yamaha outboards, 9.9 to 25 horsepower Fits Yamaha outboards, 30 to 90 horsepower Fits Yamaha outboards, 115 to 130 horsepower Fits Yamaha outboards, 150 to 250 horsepower Opens at 50 degrees Celsius (122 degrees Fahrenheit) Replaces Yamaha 6E5-12411-30-00, 688-12411-11-00, 688-12411-10-00, 688-12411-01-00, and 688-12411-00-00 Built to OEM specifications by EMP Direct replacement, no modification required for listed applications Normalized SKU: 7575100UPC Code: 840080445953

EMP 75-75014 Thermostats & PartsThis product replaces:840080459448Normalized SKU: 7575014UPC Code: 840080459448

EMP 75-75010 Thermostats & PartsThis product replaces:5001036, 840080419398Normalized SKU: 7575010UPC Code: 840080419398

EMP 75-75009 Thermostats & PartsThis product replaces:840080443133Normalized SKU: 7575009UPC Code: 840080443133

EMP 75-75003 Thermostats & PartsThis product replaces:840080493176Normalized SKU: 7575003UPC Code: 840080493176

EMP 75-75002 Thermostats & PartsThis product replaces:840080429083Normalized SKU: 7575002UPC Code: 840080429083

EMP 75-08675 Thermostats & Parts This vernatherm is a direct replacement for Johnson/Evinrude outboards covering a wide range of configurations from 1985 through 1995. It replaces BRP part number 394411 and fits 2-cylinder models rated 9.9-15 HP, 3-cylinder models rated 60-70 HP, 4-cylinder models rated 120-140 HP, 6-cylinder models rated 185-225 HP, and V8 models rated 275-300 HP. The vernatherm works as a bypass valve in the cooling system, controlling coolant flow based on engine temperature. When the engine is cold, it limits circulation to help the powerhead warm up evenly. Once operating temperature is reached, it opens fully to keep coolant moving through the system. It is a small part that does a lot of quiet work, and replacing a worn one is one of the easier ways to keep your cooling system honest. Fitment Summary: 1985-1995 Johnson/Evinrude 2-cyl, 9.9-15 HP 1985-1995 Johnson/Evinrude 3-cyl, 60-70 HP 1985-1995 Johnson/Evinrude 4-cyl, 120-140 HP 1985-1995 Johnson/Evinrude 6-cyl, 185-225 HP 1985-1995 Johnson/Evinrude V8, 275-300 HP OEM Cross-Reference: BRP: 394411 Sierra: 18-1506 GLM: 13190 Normalized SKU: 7508675UPC Code: 840080468389

EMP 75-08634 Thermostats & Parts This vernatherm is a direct replacement for Johnson/Evinrude outboards, fitting 3-cylinder models rated 60-75 HP and V4 models rated 80-140 HP. It covers production years 1985 through 1990 and replaces BRP part number 384719. A vernatherm is a temperature-sensitive bypass valve that works alongside the thermostat to regulate coolant flow through the powerhead. When the engine is cold, it restricts flow to help the engine reach operating temperature faster. Once up to temp, it opens to allow full circulation. Keeping this part in good shape is a simple way to protect against overheating and uneven cylinder temperatures. Fitment Summary: 1985-1990 Johnson/Evinrude 3-cyl, 60-75 HP 1985-1990 Johnson/Evinrude V4, 80-140 HP OEM Cross-Reference: BRP: 384719 Sierra: 18-3560 Mallory: 9-43027 Normalized SKU: 7508634UPC Code: 840080451701

EMP 75-08633 Thermostats & PartsThis product replaces:840080423791, 437090Normalized SKU: 7508633UPC Code: 840080423791

EMP 75-03950 Thermostats & PartsThis product replaces:840080428178Normalized SKU: 7503950UPC Code: 840080428178

EMP 75-03606 Thermostats & PartsEMP Thermostat Kit #75-03606Normalized SKU: 7503606UPC Code: 840080481951

EMP 75-02664 Thermostats & PartsEMP Thermostat 60c #75-02664Normalized SKU: 7502664UPC Code: 840080489544