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

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

Vendor: JLM Marine
Availability: In Stock
Product Type: Thermostat
$21.49
$25.00
$21.49
Subtotal: $21.49

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

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

$25.00 $21.49

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

$25.00 $21.49

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

This thermostat kit is engineered for a wide range of Tohatsu and Nissan 2-stroke and 4-stroke outboard motors from 2 HP to 50 HP. It ensures your engine maintains the correct operating temperature for optimal performance and longevity.

This component serves as a direct replacement for Tohatsu and Nissan OEM part numbers, including 346-01030-0, 346-01030-1, 345-01030-0, 345-01030-1, 350-01030-1, and 3H6-01030-0.

  • Maintains proper engine temperature at 50°C (122°F).
  • Engineered as a direct-fit replacement for straightforward installation.
  • Kit includes the thermostat, housing gasket, and thermostat seals for a complete service.

Part Number Cross-Reference

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

Brand Part Number
Tohatsu/Nissan 346-01030-0
Tohatsu/Nissan 346-01030-1
Tohatsu/Nissan 345-01030-0
Tohatsu/Nissan 345-01030-1
Tohatsu/Nissan 350-01030-1
Tohatsu/Nissan 3H6-01030-0
Tohatsu/Nissan 3H6-01030

Compatible Engine Models

Confirm your engine model/year in the table below.

Brand Model Rated HP Stroke OEM Part No.
Tohatsu MFS2 2 4-Stroke 346-01030
Tohatsu MFS2.5 2.5 4-Stroke 346-01030
Tohatsu MFS3.5C 3.5 4-Stroke 346-01030
Tohatsu MFS5 5 4-Stroke 346-01030
Tohatsu MF6 6 4-Stroke 346-01030
Tohatsu M8B 8 2-Stroke 346-01030
Tohatsu M9.8B 9.8 2-Stroke 346-01030
Tohatsu M9.9D2 9.9 2-Stroke 346-01030
Tohatsu M15D2 15 2-Stroke 346-01030
Tohatsu M18E2 18 2-Stroke 346-01030
Tohatsu M25C3 25 2-Stroke 346-01030
Tohatsu M30A4 30 2-Stroke 346-01030
Tohatsu MD40B, MD40B2, M40C 40 2-Stroke 346-01030
Tohatsu MD50B, MD50B2 50 2-Stroke 346-01030
Nissan NS3.5B2 3.5 2-Stroke 346-01030
Nissan NS5B2 5 2-Stroke 346-01030
Nissan NS6B2 6 2-Stroke 346-01030
Nissan NS25D2 25 2-Stroke 346-01030
Nissan NS30D2 30 2-Stroke 346-01030
Nissan NS40D2 40 2-Stroke 346-01030

Technical Specifications

Specification Value
Product Type Thermostat Kit
Installation Direct replacement
Housing Material Stainless steel housing with corrosion-resistant spring
Operating Temperature 50°C (122°F)
Other Technical Attributes Includes housing gasket and thermostat seals

Package Contents

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

Installation Guide

  1. Ensure the engine is completely cool before starting.
  2. Place a container under the engine to catch draining coolant.
  3. Locate the thermostat housing on the engine block or cylinder head.
  4. Carefully loosen and remove the bolts securing the housing cover.
  5. Remove the old thermostat and gasket. Note the thermostat's orientation.
  6. Clean the mating surfaces of the housing and cover, removing any old gasket material.
  7. Install the new thermostat in the correct orientation, followed by the new gasket and seals.
  8. Re-secure the housing cover and tighten the bolts to the manufacturer's specified torque.
  9. Refill the cooling system with the recommended coolant.
  10. Start the engine and let it warm up, checking carefully for any leaks around the housing.

Troubleshooting & FAQ

Q: How do I confirm this thermostat fits my engine?

A: This kit is designed for a wide range of Tohatsu and Nissan outboards from 2 to 50 HP. Please review the "Compatible Engine Models" table and cross-reference the OEM part number (346-01030, 345-01030, etc.) with your service manual or existing part to ensure a perfect match.

Q: What are common signs of a failing thermostat?

A: Symptoms of a bad thermostat include engine overheating, running too cold (not reaching operating temperature), erratic temperature gauge readings, and potential coolant leaks from the housing area.

Q: What temperature does this thermostat operate at?

A: This thermostat is designed to open at 50°C (122°F), ensuring the engine operates within its ideal temperature range for efficiency and longevity.

Q: Is this an OEM part?

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?

  • 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.

We can ship to virtually any address in the world with free shipping available for most regions.

For our typical US and Canadian customers , our shipping timeframes are as follows:

  • Amazon FBA: orders will be delivered within 1-5 business days after placing the order (during certain special periods such as major promotions, Christmas, etc., the delivery time of Amazon FBA may be affected).
  • US warehouse shipment: orders will be delivered within 5 days after placing the order.
  • China warehouse shipment: orders will be delivered about 12 days after placing the order.

When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.

Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.

Founded in 2002, JLM Marine has established itself as a dedicated manufacturer of high-quality marine parts, based in China. Our commitment to excellence in manufacturing has earned us the trust of top marine brands globally.

As a direct supplier, we bypass intermediaries, which allows us to offer competitive prices without compromising on quality. This approach not only supports cost-efficiency but also ensures that our customers receive the best value directly from the source.

We are excited to expand our reach through retail channels, bringing our expertise and commitment to quality directly to boat owners and enthusiasts worldwide.

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