Sierra 18-8903 Impeller for Chrysler/Force Outboards 9.9-25 HP, Replaces 47-F436065-2

The Sierra 18-8903 Impeller is a water pump impeller for Chrysler and Force outboard motors, engineered to meet or exceed the quality of the original equipment part it replaces. This impeller is the rotating component inside the outboard's water pump housing that draws raw water through the lower unit to cool the engine, and a worn or cracked impeller is a common cause of overheating. The Sierra 18-8903 is finished in white and built for reliable replacement service across a wide range of Chrysler/Force outboard horsepower ratings and model years. It is interchangeable with several original equipment and aftermarket cross-reference numbers, making it easy to identify as the correct replacement even if the old part's stamped number has worn off. Sierra's impeller is designed as a direct fit for the applications listed below, and pairing it with the corresponding impeller kit (part number 18-3240) ensures the gaskets and seals are also renewed during service. Every Sierra product is manufactured to meet or exceed OEM specifications, giving boat owners a dependable, cost-effective alternative to buying through the original equipment manufacturer.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-8903
• Category: Chrysler Outboard Impeller
• Weight: 0.12 pounds
• Color: White
• Material: Aluminum
• UPC: 808282106669
• OEM Cross-Reference: Chrysler/Force/US Marine 47-F436065-2, GLM 89614, Mallory 9-45004
• Companion Impeller Kit Part Number: 18-3240

Fitment

• Chrysler/Force 9.9 HP, 1979-1997, all serial numbers
• Chrysler/Force 10 HP, 1974-1978, all serial numbers
• Chrysler/Force 12 HP, 1979, all serial numbers
• Chrysler/Force 15 HP, 1974-1997, all serial numbers
• Chrysler/Force 20 HP, 1973-1978, all serial numbers
• Chrysler/Force 25 HP, 1973-1978, all serial numbers

Replaces (OEM)

• Chrysler/Force/US Marine 47-F436065-2
• GLM 89614
• Mallory 9-45004

Frequently Asked Questions

What outboards does the Sierra 18-8903 impeller fit? It fits Chrysler/Force outboards including 9.9 HP (1979-1997), 10 HP (1974-1978), 12 HP (1979), 15 HP (1974-1997), 20 HP (1973-1978), and 25 HP (1973-1978), all serial numbers within those ranges.

Is the Sierra 18-8903 an OEM part or an aftermarket replacement? The 18-8903 is a Sierra aftermarket impeller manufactured to meet or exceed the specifications of the original equipment part it replaces, rather than a part sourced from Chrysler or Force directly.

What OEM numbers cross-reference to the Sierra 18-8903? The Sierra 18-8903 is interchangeable with Chrysler/Force/US Marine part number 47-F436065-2, GLM 89614, and Mallory 9-45004.

How much does the Sierra 18-8903 impeller weigh? The Sierra 18-8903 impeller weighs 0.12 pounds.

What material is the Sierra 18-8903 impeller made from? The Sierra 18-8903 is made from aluminum and finished in white.

Do I need any other parts to install the Sierra 18-8903? The 18-8903 impeller pairs with impeller kit 18-3240, which supplies the associated gaskets and seals for a complete water pump service on compatible Chrysler/Force outboards.

Will the Sierra 18-8903 fit a 1998 model year Chrysler/Force outboard? No. The 18-8903 covers 1973 through 1997 model years across its listed horsepower ranges; 1998 applications use a different impeller part number.

What does a worn impeller like the 18-8903 cause if not replaced? A worn or cracked impeller reduces raw water flow through the outboard's cooling system, which can lead to engine overheating, so the Sierra 18-8903 should be replaced if it shows cracking, curling, or missing vanes.

Is the Sierra 18-8903 sold as a single impeller or a full kit? The 18-8903 is the impeller itself; the matching impeller kit, part number 18-3240, is sold separately for buyers who also want new gaskets and seals.

What color is the Sierra 18-8903 impeller? The Sierra 18-8903 impeller is white.

Does the Sierra 18-8903 fit both 9.9 HP and 25 HP Chrysler/Force outboards? Yes, the same 18-8903 impeller is specified across multiple Chrysler/Force horsepower ratings, including 9.9 HP, 10 HP, 12 HP, 15 HP, 20 HP, and 25 HP within their respective listed years.

How can I confirm the Sierra 18-8903 is the correct impeller for my engine? Match your Chrysler/Force outboard's horsepower and model year against the listed fitment for the 18-8903, or compare the old impeller against cross-reference numbers 47-F436065-2, GLM 89614, or Mallory 9-45004.