Thermostat Repair Service Kit for Nissan Tohatsu MFS MF M MD 2-50 HP Outboard Motors 346-01030

Thermostat Repair Kit – Fits Tohatsu/Nissan Outboard Motors 2-50 HP (Replaces 346-01030, 345-01030)

This thermostat repair kit is designed for a wide range of Tohatsu and Nissan 2-stroke and 4-stroke outboard motors, from 2 to 50 HP. It includes the essential components to restore the engine's cooling system to its proper operating temperature.

This kit is a direct replacement for Tohatsu/Nissan OEM part numbers: 346-01030-0, 346-01030-1, 345-01030-0, 345-01030-1, 350-01030-1, and 3H6-01030-0.

• Complete Kit: Includes the thermostat, housing gasket, and seals for a full replacement.
• Precise Temperature Control: Features a thermostat rated for 50°C (122°F) to ensure optimal engine performance.
• Simple Installation: Designed as a direct, bolt-in replacement for the original factory parts.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

• 1 x Thermostat (Replaces 346-01030)
• 1 x Thermostat Housing Gasket
• 2 x Thermostat Seals

Installation Guide

1. Ensure the engine is off and cool. Disconnect the battery terminals.
2. Drain the engine coolant completely to avoid spills.
3. Locate the thermostat housing on the engine. It is typically a small dome-shaped cover with two or three bolts.
4. Carefully remove the bolts and the housing cover. Note the orientation of the old thermostat.
5. Remove the old thermostat and the gasket/seals from the housing.
6. Thoroughly clean the mating surfaces of the housing and cover, removing any old gasket material.
7. Install the new thermostat in the same orientation as the original.
8. Place the new gasket and seals into position.
9. Re-install the housing cover and tighten the bolts to the torque specified by the manufacturer.
10. Refill the cooling system with the appropriate coolant.
11. Reconnect the battery, start the engine, and carefully check for any leaks around the housing.

Troubleshooting & FAQ

How do I confirm this kit fits my Tohatsu/Nissan engine?

This kit is designed for a wide range of Tohatsu and Nissan 2-50 HP models. Please review the "Compatible Engine Models" table and cross-reference the OEM part numbers (e.g., 346-01030, 345-01030) with your original part to ensure an exact match.

What are the signs of a failing thermostat?

Common symptoms include engine overheating at idle or low speeds, the engine taking too long to reach its normal operating temperature, or inconsistent readings on the temperature gauge.

What is the operating temperature of this thermostat?

This thermostat is rated to open at 50°C (122°F), ensuring your engine warms up quickly and maintains the correct temperature for efficient performance and longevity.

OEM vs. Aftermarket?

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.

How fast do you ship and how much does it cost?

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.

What is your warranty and return policy?

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?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.