Engineered Marine Products Impeller Service Kit, Replaces 18-3217, for MerCruiser Alpha/MR Water Pump

This impeller service kit from Engineered Marine Products (part number 46-00091) is built as a direct cross-reference for OEM Mercury/MerCruiser part 18-3217, used in the water pump housing of MerCruiser sterndrive units. It is manufactured to OEM standards, giving boat owners and marine technicians a reliable, cost-effective option when servicing the cooling system water pump on compatible MerCruiser Alpha One and MR sterndrives.

The kit carries a machined exterior finish and measures 4 x 1.62 x 4 inches, with a shipping weight of 0.356 pounds, making it a compact, easy-to-handle part for routine water pump maintenance. Per the manufacturer's fitment chart, part 18-3217 is specified for MerCruiser drive units within the serial number range 2495186 through 0D594568, covering standard housing configurations, units without a flush screw in the gear housing, and MR/Alpha I applications. Drives that fall outside this serial range, such as Alpha One Generation II, Vazer, Bravo, or inboard applications with plastic or brass pump bodies, use different part numbers per the same chart.

Regular impeller service is a routine part of MerCruiser cooling system maintenance, and using a correctly cross-referenced kit like the 46-00091 helps keep the water pump operating properly.

Specifications

• Brand: Engineered Marine Products
• Manufacturer Part Number: 46-00091
• UPC: 840080491783
• Product Dimensions: 4 x 1.62 x 4 inches
• Weight: 0.356 pounds
• Finish: Machined
• OEM Cross Reference: 18-3217
• Application: MerCruiser I/O cooling system water pump

Fitment

• MerCruiser Alpha One and MR sterndrive water pump housings, drive unit serial numbers 2495186 through 0D594568

Replaces (OEM)

• 18-3217

Frequently Asked Questions

What OEM part number does the Engineered Marine Products 46-00091 impeller kit replace? It cross-references Mercury/MerCruiser part number 18-3217.

Which MerCruiser drives is the 46-00091 impeller service kit designed for? MerCruiser Alpha One and MR sterndrive water pump housings within drive unit serial number range 2495186 through 0D594568 are the specified application for this kit.

Will this kit fit an Alpha One Generation II or Vazer drive? No. The 46-00091 kit is specified for the 2495186 through 0D594568 serial range; Alpha One Generation II and Vazer drives use a different water pump part number per the manufacturer's fitment chart.

What are the dimensions of the 46-00091 impeller service kit? The kit measures 4 x 1.62 x 4 inches.

How much does the 46-00091 impeller kit weigh? It weighs 0.356 pounds.

Is the 46-00091 a genuine OEM part or an aftermarket equivalent? It is manufactured by Engineered Marine Products as an aftermarket kit built to OEM standards and cross-referenced to Mercury/MerCruiser part 18-3217, not a Mercury/MerCruiser-branded part.

What finish does the 46-00091 impeller kit have? It has a machined exterior finish.

What is the UPC for the 46-00091 impeller service kit? The UPC is 840080491783.

Does the 46-00091 kit fit Bravo or inboard MerCruiser applications? No. Bravo and inboard units with plastic or brass water pump bodies use separate part numbers per the manufacturer's fitment chart, different from the 18-3217 cross-reference used by the 46-00091 kit.

How does the 46-00091 compare to buying the OEM Mercury 18-3217 part directly? The Engineered Marine Products 46-00091 is built to OEM standards as a direct cross-reference for part 18-3217, offering the same application on compatible MerCruiser Alpha One and MR sterndrives.