803750A03 Water Pump Impeller Repair Kit - Reliable Engine Cooling

In this review the 803750A03 Water Pump Impeller Repair Kit is evaluated for owners of small outboard engines who need a dependable and complete repair solution. The kit is aimed at Mercury 8HP, 9.8HP and 9.9HP 209cc motors and compatible Nissan Tohatsu models; the biggest reason to buy is that it supplies every needed component for a full water pump rebuild in one package, so a stranded weekend on the water can often be avoided. The reviewer found the included parts to be a precise fit and straightforward to install for anyone comfortable with basic outboard maintenance.

Key Features

• Complete kit: Includes the water pump impeller, driveshaft pin, insert cup, wear plate, gaskets, bolts and washers so you do not have to source individual parts.
• Compatibility: Designed for Mercury 8HP, 9.8HP and 9.9HP 209cc motors and also fits Nissan Tohatsu 8 and 9.8HP outboard water pumps for broad applicability.
• Correct replacement numbers: Matches factory part numbers such as Mercury 46-803750A03 and Tohatsu 3B2-87322-2 which helps ensure correct fitment.
• Service-ready: The package provides the typical wear items needed during a water pump service, reducing the chance of missing components during a rebuild.
• Value packaging: Buying the repair kit is more convenient and often less expensive than purchasing parts separately when performing a standard impeller replacement.

Who It's For

This kit is best for boat owners, DIY mechanics, and small marinas that maintain Mercury 8HP, 9.8HP and 9.9HP 209cc outboards or the equivalent Nissan Tohatsu 8 and 9.8HP models. It is particularly useful for anyone who prefers to carry a complete service kit aboard or keep a single spare on hand for seasonal maintenance.

It is less suitable for someone who lacks basic mechanical skills or tools; a professional installation is recommended if you are not comfortable disassembling the lower unit. Also, verify engine model details before purchase because the kit is specific to the compact 209cc family of engines and close compatibility must be confirmed.

Pros & Cons

Pros

• Quality components that customers report fit well and restore engine cooling performance.
• All necessary parts included in one package, saving time sourcing individual items.
• Matches known factory part numbers so fitment is predictable for supported engines.

Cons

• Not universal; limited to the listed Mercury and Tohatsu small outboard models so buyers must confirm compatibility.

Specifications

Product type	Water pump impeller repair kit
Compatible engines	Mercury 8HP, 9.8HP, 9.9HP 209cc and Nissan Tohatsu 8/9.8HP
Included parts	Impeller, driveshaft pin, insert cup, wear plate, gaskets, bolts, washers
Mercury part numbers	46-803750A03, 80375A03, 803748Q01, 803748K01
Tohatsu part numbers	3B2873222M, 3B2-87322-2

Our Verdict

The 803750A03 repair kit is a sensible purchase for owners of the small Mercury and Tohatsu outboards it supports because it supplies every wear item needed for a standard water pump service and matches factory part numbers for reliable fit. For DIYers and service shops this is good value compared with sourcing parts individually, though buyers should confirm engine compatibility before ordering.

Frequently Asked Questions

Will this kit fit my Mercury 9.9HP outboard?
Yes, it is specified for Mercury 9.9HP 209cc engines but you should confirm your motor model matches the 209cc family before purchasing.

Are all necessary hardware pieces included?
Yes, the package includes the impeller, driveshaft pin, insert cup, wear plate, gaskets, bolts and washers as shown in the product image.

Is professional installation required?
Not required for experienced DIYers with basic tools, but a professional is recommended if you are unfamiliar with lower unit disassembly.