Cooling System Thermostat – Polaris Sportsman / Scrambler / Magnum / Hawkeye / Ranger (1995–2014)

Ensure your Polaris engine reaches and maintains the correct operating temperature with this direct-fit aftermarket cooling system thermostat. Designed as a replacement for a wide range of Polaris ATV and UTV models, this thermostat helps prevent overheating, ensures efficient fuel combustion, and supports reliable engine performance across demanding off-road conditions.

Engineered to meet or exceed original equipment specifications, this thermostat provides a precise, plug-and-play installation. It replaces worn or stuck thermostats to restore proper coolant flow, helping your engine warm up quickly and run smoothly during trail rides or farm work.

Comprehensive Vehicle Fitment

Product Specifications

OEM & Aftermarket Cross-Reference Information

OEM cross-reference numbers are provided for reference purposes only. Always verify fitment using your machine's exact model, year, and original part number before ordering.

What's Included

This kit includes:

• (1) Aftermarket Replacement Thermostat

Note: Some applications may require reusing the existing O-ring or gasket; a replacement O-ring is not included with all thermostat kits .

Why Choose This Aftermarket Replacement?

• Direct-Fit Compatibility: Precision-engineered for a vast range of Polaris 400, 500, and 550cc 4-stroke models, including Sportsman, Scrambler, Magnum, Hawkeye, and Ranger across nearly two decades.

• OEM Cross-Reference: Cross-references genuine Polaris part numbers 3084940 and 3090049 for confident replacement .

• Essential Cooling System Function: The thermostat regulates coolant flow, allowing the engine to reach operating temperature quickly and preventing it from overheating under load.

• Restores Engine Efficiency: A properly functioning thermostat ensures optimal fuel combustion, smooth idling, and consistent power delivery.

• Durable Construction: Manufactured from quality materials to meet or exceed original factory pump standards .

• Cost-Effective Maintenance: A reliable aftermarket alternative to expensive OEM parts, perfect for routine cooling system maintenance.

Installation Notes:

• Always work on a cool engine to avoid the risk of burns from hot coolant.

• Consult your service manual for the exact location of the thermostat on your specific model.

• Note that the cooling system may need to be bled of air after installation.

• Some online reviews suggest checking the fit of the included O-ring; you may need to reuse the original if the new one is too thin to prevent leaks .

• After installation, run the engine and check for proper warm-up and any signs of coolant leaks.

Why Upgrade?

A stuck or failing thermostat is a common cause of engine overheating or failure to reach operating temperature. This leads to poor performance, increased fuel consumption, and potential engine damage. Restore your Polaris engine's thermal stability with this quality aftermarket cooling system thermostat, designed to keep you riding with confidence.

Order your cooling system thermostat today and get back on the trail with confidence.

Comprehensive Vehicle Fitment

Compatibility data compiled from Polaris model coverage and retailer listings for RM17201 aftermarket thermostat references.

Product Specifications

Specs are corroborated by retailer listings noting 30 mm diameter, included O-ring, and an 82°C opening temperature.

OEM & Aftermarket Cross-Reference Information

OEM cross-reference details are drawn from Polaris compatibility listings and retailer data indicating the RM17201 as the aftermarket replacement for the two OEM numbers.

What's Included

Includes one thermostat with a pre-installed seal.

• Thermostat
• Seal / O-ring

Related parts such as hoses, clamps, or thermostat housing gaskets are not included unless specified.

Source data confirming the package contents comes from retailer listings showing 1-piece thermostat with seal.

Why Choose This Aftermarket Replacement?

• Direct-Fit Compatibility: Precisely matched 30 mm opening thermostat for a broad Polaris lineup, reducing install hassle and fit issues.
• OEM Cross-Reference: Replaces Polaris OEM numbers 3090049 and 3084940, maintaining original cooling performance without OEM price tag.
• Premium Materials: Durable metal housing with reliable sealing components to resist oil exposure and corrosion in harsh environments.
• Temperature Regulation: Reliable opening around 82°C to ensure proper warm-up and effective cooling under load.
• Reliability for Work & Trail: Built to endure constant heat cycles and rough terrain, making it a dependable choice for both farming tasks and off-road duty.
• Cost-Effective Value: A smart aftermarket option that preserves engine health without the higher OEM price.

Installation Notes:

• Ensure the engine is fully cool before starting; opening a hot cooling system can cause burns and injuries.
• Disconnect the battery and remove the intake or access panel as needed to reach the thermostat housing.
• Detach the hose from the thermostat housing, then carefully remove the old unit and clean the mating surfaces to remove any gasket residue.
• Install the new thermostat with the correct orientation, insert the new O-ring seal, and lightly lubricate the seal with coolant or clean motor oil to aid seating.
• Reconnect the hose, purge air from the cooling system, and refill with the correct coolant mix; bleed any remaining air until there are no bubbles.
• Start the engine and monitor for leaks; run to operating temperature and verify stable temperature readings and normal fan operation.

Why Upgrade?

A worn or sticking thermostat can cause overheating, reduced cooling efficiency, and erratic engine temperatures, all of which stress bearings and seals. Upgrading to this aftermarket thermostat restores reliable opening at the correct temperature, promoting consistent cooling, proper warm-up, and long-term engine reliability in demanding conditions.