Temperature Sensor for Mercury Mariner Verado Outboards – 135HP to 400HP
This air temperature sensor is engineered to fit Mercury Verado and Mariner outboard engines ranging from 135HP to 400HP, as well as select MerCruiser Race Stern Drive models. Designed as a direct replacement for OEM part numbers 891663 and 891663001, this sensor ensures reliable air temperature monitoring for optimal engine performance across a wide range of Mercury marine applications.
Whether you're maintaining a Verado high-performance outboard or a MerCruiser stern drive, this temperature sensor delivers OEM-quality construction and accuracy. It replaces the factory air temperature sensor, helping your engine management system maintain proper fuel-air mixture and operating efficiency.
- Compatible with Mercury Verado and Mariner outboards from 135HP to 400HP
- Also fits MerCruiser Race Stern Drive models: 850 SCI, 1075 SCI, 1200 SCI
- Direct replacement for Mercury OEM part numbers 891663 and 891663001
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury / Mariner |
891663 |
| Mercury / Mariner |
891663001 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here's a guide to help you identify your engine's serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| Brand |
Model |
Rated HP |
OEM Part No. |
| Mercury |
Verado Outboard |
135HP, 150HP, 175HP, 225HP, 250HP, 275HP, 300HP, 350HP, 400HP |
891663, 891663001 |
| Mariner |
Outboard |
135HP, 150HP, 175HP, 225HP, 250HP, 275HP, 300HP, 350HP, 400HP |
891663, 891663001 |
| MerCruiser |
Race Stern Drive |
850 SCI, 1075 SCI, 1200 SCI |
891663, 891663001 |
Technical Specifications
| Specification |
Value |
| Sensor Type |
Air Temperature Sensor |
| OEM Part Number |
891663, 891663001 |
| Application |
Mercury Verado & Mariner Outboards, MerCruiser Race Stern Drives |
Package Contents
Your package includes:
- 1 x Air Temperature Sensor
Installation Guide
- Disconnect the negative battery cable to ensure safe working conditions.
- Locate the original air temperature sensor on your engine; consult your service manual or parts diagram if needed.
- Carefully disconnect the electrical connector from the old sensor.
- Remove the mounting hardware (typically a single bolt or clip) securing the sensor in place.
- Extract the old sensor and inspect the mounting area for dirt or corrosion; clean if necessary.
- Insert the new air temperature sensor into the mounting bracket or port.
- Secure the sensor with the original mounting hardware, tightening to the manufacturer's recommended torque.
- Reconnect the electrical connector, ensuring it clicks or locks firmly into place.
- Verify that all connections are secure and that no wires are pinched or exposed.
- Reconnect the negative battery cable and start the engine to confirm proper sensor function.
- Monitor engine performance and check for any warning lights or error codes.
- If any issues arise, re-check all connections and consult your service manual.
Troubleshooting & FAQ
Q: How do I confirm this temperature sensor fits my engine?
A: Check the compatibility table above for your engine brand, model, and horsepower. You can also verify the OEM part number (891663 or 891663001) on your existing sensor or in your engine's parts diagram.
Q: What are the signs that my air temperature sensor needs replacement?
A: Common symptoms include rough idling, poor fuel economy, engine warning lights, or difficulty starting in varying temperature conditions. If your engine management system cannot accurately read air temperature, performance will suffer.
Q: How often should I replace this sensor?
A: Air temperature sensors typically last several years under normal conditions. Replace it if you experience performance issues, error codes related to air intake temperature, or physical damage to the sensor or wiring.
Q: Is this sensor compatible with both 4-stroke Verado engines and older models?
A: This sensor is designed specifically for Mercury Verado and Mariner outboards in the 135HP to 400HP range, as well as select MerCruiser Race Stern Drive models. Always verify using the OEM part number and compatibility table.
Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.