Thermostat Kit with Hoses for Johnson/Evinrude V4 Crossflow 2-Stroke Outboards, 65–140 HP
Thermostat Kit with Hoses for Johnson/Evinrude V4 Crossflow 2-Stroke Outboards, 65–140 HP is backordered and will ship as soon as it is back in stock.
Worry-free returns
Worry-free returns
Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.
If the return is due to our error or a defective item, we’ll make it right.
Please contact us before returning any item.
Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Thermostat Kit with Hoses for Johnson/Evinrude V4 Crossflow 2-Strok...
Thermostat Kit with Hoses for Johnson/Evinrude V4 Crossflow 2-Stroke Outboards, 65–140 HP is backordered and will ship as soon as it is back in stock.
Product Details
This thermostat and hose service kit is designed for selected Johnson/Evinrude 2-stroke V4 Crossflow outboard engines in the 65–140 HP range. The listed applications include selected Jet and standard models from approximately 1978 through 1995. Because fitment varies by model, year, and engine configuration, compare the complete application information and the numbers on your existing components before ordering.
The kit is intended to renew the thermostat assemblies and associated cooling-system service components, including the port and starboard thermostat hoses listed below. It is an aftermarket replacement kit and is not an original Johnson/Evinrude OEM package.
- For selected Johnson/Evinrude V4 Crossflow 2-stroke outboards.
- Includes thermostat assemblies, gaskets, relief-valve components, springs, grommets, and two cooling hoses.
- Thermostat rating listed for this kit: 143°F (62°C).
- Confirm the exact model, year, horsepower, and component numbers before installation.
Part Number Matrix
The following numbers are reference numbers associated with the thermostat kit and its included components. They should be used for comparison, not as a substitute for checking the complete engine application.
| Component or Brand | Reference Number |
|---|---|
| Johnson/Evinrude thermostat reference | 18-3673 |
| Sierra thermostat reference | 18-3673 |
| GLM thermostat reference | 13270 |
| OMC thermostat reference | 434841 |
| Kit thermostat component references | 393659, 434841, 378065, 508626, 5005440, 18-3543 |
| Thermostat hose references | 340975, 340976 |
| Starboard hose references | 340975, 18-70936, 321724 |
| Port hose references | 340976, 18-70937 |
| Additional kit component references | 332369, 18-0977; 321932, 18-0675; 318395, 18-3564; 321692, 18-2391; 317245, 18-1243 |
Engine & Model Compatibility
The applications below represent the listed V4 Crossflow coverage. Engine model designations and production years can overlap, so verify the identification plate and the existing thermostat and hose arrangement before purchase.
| Brand | Model Family | Rated HP | Stroke | Years | Related Reference Numbers | Notes |
|---|---|---|---|---|---|---|
| Johnson/Evinrude | V4 Crossflow | 65 Jet | 2-Stroke | 1994–1995 | 18-3673, 340975, 340976 | Verify the Jet configuration. |
| Johnson/Evinrude | V4 Crossflow | 80 Jet | 2-Stroke | 1994–1995 | 18-3673, 340975, 340976 | Verify the Jet configuration. |
| Johnson/Evinrude | V4 Crossflow | 90 Jet | 2-Stroke | 1994 | 18-3673, 340975, 340976 | Verify the exact model designation. |
| Johnson/Evinrude | V4 Crossflow | 85 | 2-Stroke | 1978–1980, 1993–1995 | 18-3673, 340975, 340976 | Confirm year and configuration. |
| Johnson/Evinrude | V4 Crossflow | 88 | 2-Stroke | 1984–1995 | 18-3673, 340975, 340976 | Confirm year and configuration. |
| Johnson/Evinrude | V4 Crossflow | 90 | 2-Stroke | 1983–1995 | 18-3673, 340975, 340976 | Confirm year and configuration. |
| Johnson/Evinrude | V4 Crossflow | 100 | 2-Stroke | 1979–1980, 1990–1995 | 18-3673, 340975, 340976 | Confirm year and configuration. |
| Johnson/Evinrude | V4 Crossflow | 100 Commercial | 2-Stroke | 1984–1989 | 18-3673, 340975, 340976 | Confirm the Commercial model. |
| Johnson/Evinrude | V4 Crossflow | 110 | 2-Stroke | 1985–1989 | 18-3673, 340975, 340976 | Confirm year and configuration. |
| Johnson/Evinrude | V4 Crossflow | 112 | 2-Stroke | 1994–1995 | 18-3673, 340975, 340976 | Confirm year and configuration. |
| Johnson/Evinrude | V4 Crossflow | 115 | 2-Stroke | 1978–1995 | 18-3673, 340975, 340976 | Confirm year and configuration. |
| Johnson/Evinrude | V4 Crossflow | 140 | 2-Stroke | 1978–1985 | 18-3673, 340975, 340976 | Confirm year and configuration. |
Technical Specifications
- Product Type
- Thermostat and cooling-hose service kit
- Application
- Selected Johnson/Evinrude V4 Crossflow 2-stroke outboards
- Horsepower Range
- 65–140 HP, subject to the application table
- Installation
- Replacement service installation
- Fuel Type
- Gasoline
- Fitting Style
- OEM-style replacement fittings
- Housing Materials
- Aluminum and plastic components are included or associated with the listed service assembly
- Package Dimensions
- 20.4 × 10.3 × 4.2 cm (8.03 × 4.06 × 1.65 inches), as listed
- Package Weight
- 0.23 kg (8.1 oz), as listed
- Thermostat Rating
- 143°F (62°C), as listed
- Product Status
- Aftermarket replacement; not an original OEM component
What's in the Box
- 2 × thermostats; associated reference numbers include 393659, 434841, 378065, 508626, 5005440, and 18-3543.
- 2 × gaskets; associated reference numbers include 332369 and 18-0977.
- 2 × thermostat gaskets; associated reference numbers include 321932 and 18-0675.
- 2 × poppet relief valves; associated reference numbers include 318395 and 18-3564.
- 2 × grommets; associated reference numbers include 321692 and 18-2391.
- 2 × valve springs; associated reference numbers include 317245 and 18-1243.
- 1 × starboard hose; associated reference numbers include 340975, 18-70936, and 321724.
- 1 × port hose; associated reference numbers include 340976 and 18-70937.
Installation Notes
- Turn off the engine, allow it to cool completely, and disconnect the battery where applicable.
- Close or disconnect the water supply as appropriate for the boat and engine, and prepare for residual water.
- Locate the thermostat housings and document the routing and position of the existing hoses.
- Remove the housing covers and carefully detach the old hoses.
- Remove the old thermostats, gaskets, poppet valves, springs, grommets, and related service components.
- Clean the mating surfaces and inspect the covers and housings for corrosion, damage, or blockage.
- Install the replacement poppet valves, springs, and grommets in their original locations.
- Install the thermostats and gaskets in the correct orientation.
- Route and attach the starboard and port hoses to the matching fittings.
- Reinstall the housing covers and tighten the fasteners to the engine manufacturer's specified torque.
- Restore the normal water supply and operate the engine according to the manufacturer's procedure.
- Check for leaks and confirm that the engine reaches and maintains its normal operating temperature.
Troubleshooting & FAQ
How do I confirm fitment?
Compare your exact Johnson/Evinrude model, year, horsepower, stroke, and engine configuration with the application table. Also compare the thermostat and hose arrangement and the reference numbers on the parts being replaced.
What are common signs of a thermostat problem?
Possible symptoms include overheating, running too cold, inconsistent temperature behavior, restricted water flow, or water leakage around a thermostat housing. These symptoms can also have other causes and should be diagnosed before replacement.
Why replace the hoses and thermostat components together?
Hoses, gaskets, valves, springs, and thermostats are all part of the cooling-system service area. Replacing worn related components together can reduce the need to reopen the housing, provided the kit matches the engine configuration.
What if the engine still overheats after installation?
Inspect the water-pump impeller, water passages, thermostat orientation, poppet-valve operation, hose routing, housing surfaces, and water supply. Continued overheating requires further diagnosis and should not be ignored.
Is this an OEM kit?
No. This listing is for an aftermarket replacement kit. The reference numbers are provided to assist comparison and are not a statement that the kit is manufactured by Johnson/Evinrude, OMC, Sierra, or GLM.
Should installation be performed by a professional?
Professional installation is recommended when you are unfamiliar with outboard cooling systems, torque requirements, or the correct thermostat and poppet-valve orientation.
Safety & Important Information
- Work only on a cool, secured engine and follow the engine manufacturer's service procedures.
- Do not operate the engine if cooling-water flow is inadequate or if overheating continues.
- Verify the model, year, horsepower, stroke, configuration, hose routing, and reference numbers before ordering.
- Package contents and reference numbers should be compared with the actual parts supplied when received.
- This is an aftermarket replacement, not an original OEM component.
About Sea Sierra
- Marine Replacement Parts — We provide aftermarket components for common marine service applications.
- Application-Focused Information — Product references and application details are supplied to help customers compare replacement parts.
- Support for Installation Planning — Confirming the complete engine identification before purchase helps reduce fitment errors.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
