Water Pump Impeller Kit – Fits OMC Stringer 400-800 Series Stern Drives (Replaces 983218, 18-3386)

$66.99

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Water Pump Impeller Kit – Fits OMC Stringer 400-800 Series Stern Drives (Replaces 983218, 18-3386) is backordered and will ship as soon as it is back in stock.

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You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

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Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This complete Water Pump Impeller Kit is designed for OMC Stringer 400 and 800 series stern drives from 1962–1985, including 4-cylinder, V6, and V8 models. It provides a reliable, direct-fit solution for maintaining your engine's cooling system. Note: This kit does not fit OMC Cobra models.

It serves as a direct interchange for several part numbers, including OMC 983218, Sierra 18-3386, and GLM 12190, ensuring broad compatibility for repairs and maintenance.

Engineered as a direct replacement for original factory parts.
Includes the water pump housing, impeller, wear plate, and all necessary O-rings and seals.
Constructed from durable, marine-grade materials to meet or exceed OEM specifications.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket brands.

Brand	Part Number
OMC	983218
OMC	0983218
OMC	0778061
Sierra	18-3386
Sierra	18-3286
GLM	12190
Mallory	9-45286
SEI Marine	96-105-09K
OBR Red Rhino	OS-152
SOXA Marine	23KO449
JLM Marine	46-00017

Engine & Model Compatibility

Confirm your engine model and year in the table below to ensure correct fitment.

OMC Stringer Models: This kit is exclusively for OMC Stringer stern drives made between 1962 and 1985. It is not compatible with OMC Cobra models. For Cobra drives, please use part number 984461 or Sierra 18-3348.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
OMC	Stringer 400	100-140	4-Stroke	1962–1985	983218	Upper gear housing - Stringer mount
OMC	Stringer 800	170-260	4-Stroke	1962–1985	983218	Upper gear housing - Stringer mount
OMC	2.0-3.0L	100-140	4-Stroke	1962–1985	983218	4-cylinder
OMC	4.3L	165	4-Stroke	1962–1985	983218	V6
OMC	5.0-6.2L	170-260	4-Stroke	1962–1985	983218	V8

Technical Specs

Product Type: Water Pump Impeller Repair Kit with Housing
Installation: Direct replacement for OMC Stringer stern drives
Housing Material: Marine-grade materials meeting OEM specifications
Fitting Type: Direct fit to OEM specifications
Warranty: Varies by manufacturer, typically 1 year limited warranty
Other Technical Attributes: Produced in ISO9002 certified factories (JLM Marine)

What’s in the Box

Kit contents may vary slightly between aftermarket manufacturers. A typical complete kit includes:

1 x Impeller Housing (Replaces 983298)
2 x Rubber Seal (Replaces 907774)
1 x Wear Plate (Replaces 313176)
1 x Impeller (Replaces 379475)
1 x O-Ring (Replaces 310584)
1 x O-Ring (Replaces 310585/310967)
1 x O-Ring (Replaces 314491)

Installation Notes

Professional installation is recommended. The following are general, model-agnostic steps:

Disconnect the boat's battery before starting work.
Place the drive in forward gear to simplify reassembly.
Drain the gearcase oil completely.
Remove the lower unit (outdrive) from the upper housing. This may require removing bolts under the trim tab anode.
Unscrew the bolts securing the old water pump housing to the lower unit.
Remove the old housing, impeller, wear plate, seals, and O-rings. Note their orientation.
Thoroughly clean the housing seat and driveshaft.
Install the new components in reverse order. Lightly grease the new O-rings and interior of the pump housing.
Align the impeller key and turn the driveshaft clockwise while pressing down to install the impeller.
Torque housing bolts to manufacturer specifications.
Reinstall the lower unit, refill with fresh gear oil, and connect the battery.
Test the engine on a water supply (flusher) to verify proper water flow.

Troubleshooting & FAQ

How do I know if this kit fits my OMC engine?

This kit is specifically for OMC Stringer series stern drives (400-800 models) from 1962–1985. Please verify your model against the compatibility table. Critically, ensure you do not have an OMC Cobra drive, as this part will not fit.

What are the symptoms of a failing water pump impeller?

Common signs include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and a dry, cracked, or deformed appearance upon visual inspection.

What is the recommended replacement interval for an impeller?

For preventative maintenance, it is best practice to replace the impeller every one to two years, or every 100-200 hours of operation, especially for boats used in saltwater or sandy conditions.

Will this kit fit an OMC Cobra stern drive?

No, absolutely not. This kit is only for the older OMC Stringer drives. Cobra drives require a different water pump kit (typically part number 984461 or Sierra 18-3348).

Does this kit include the pump housing?

Yes, this is a complete kit that includes the water pump housing, impeller, wear plate, seals, and o-rings necessary for a full replacement.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. The part is manufactured in an ISO 9002 facility and batch-inspected for consistency and quality.

Shipping speed & cost?

We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free for most orders, with expedited options available at checkout where applicable.

Warranty & returns?

This product is covered by a 1-year warranty against manufacturing defects under normal use. If any issues arise, contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. See our policy page or reach out for instructions.

Safety & Important Info

Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement component, not an Original Equipment Manufacturer (OEM) part.
Professional installation is recommended for safety and performance. Incorrect installation can lead to engine damage.

About Sea Sierra

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world reliability.
Fast Global Fulfillment — We offer free standard delivery to most regions, with an average transit time of 5–15 days.
Manufacturer-Direct Value — Our parts deliver fair pricing without compromising on high-quality materials or stringent quality control.

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