Sierra 3071 Yamaha Impeller

The Sierra 3071 (18-3071) Impeller is a six-blade replacement lower-unit water pump impeller for compatible Yamaha outboards. It rotates inside the water pump housing to draw cooling water through the gearcase and circulate it through the engine. Replaces Yamaha OEM impeller numbers 6E5-44352-00-00 and 6E5-44352-01-00.

Parts Desk Insight Best Use

Note that 47-3071 can resemble a Mercury-style OEM number but is the distributor SKU for Sierra 18-3071. The primary OEM cross-reference is Yamaha 6E5-44352-00-00 or 6E5-44352-01-00 confirm that number in the engine parts diagram before removing the lower unit. Yamaha used the 6E5-series impeller across multiple high-HP engine families and years (115250 HP, including F225, LF225 3.3L, and VF225 SHO 4.2L), so model number and production year verification is essential.

Replace every 23 seasons or 200 hours regardless of visible wear. At 156 grams, this is one of the larger impellers in the Sierra Yamaha range sized for high-volume cooling demands on big four-stroke outboards.

Key Specifications

• Sierra part number: 18-3071
• Six flexible impeller blades
• Fits compatible Yamaha 115250 HP outboards (including F225, LF225 3.3L, VF225 SHO 4.2L)
• Impeller only housing, wear plate, key, seals, and gaskets not included
• UPC: 030999315236

Engine Compatibility

Documented applications include compatible Yamaha outboards using OEM impeller 6E5-44352-00-00 or 6E5-44352-01-00:

• 115 HP applications
• 150 HP applications
• 175 HP applications
• 200 HP applications
• 250 HP applications
• F225, LF225 3.3L, and VF225 SHO 4.2L models

Always confirm by complete engine model number, production year, serial number, gearcase configuration, and OEM water pump parts diagram. Do not order by horsepower alone.

Alternate Part Numbers

• Sierra: 18-3071 / 118-3071
• Yamaha: 6E5-44352-00-00, 6E5-44352-01-00
• GLM Marine: 89930
• Mallory Marine: 9-45609, 9-45609-10

Installation Notes

Lower-unit removal is required to access the water pump assembly. During service: inspect the pump housing, stainless cup, wear plate, key, seals, and driveshaft; remove any broken impeller fragments from the pump and cooling passages; lubricate the new impeller with clean soapy water or approved assembly lubricant; rotate the driveshaft in its normal operating direction while seating the housing over the blades. Confirm strong cooling-water telltale flow before operating under load. Never operate the outboard without an adequate cooling-water supply.

Compatible Yamaha Water Pump Kits

• Sierra 3433 Yamaha Water Pump Repair Kit
• Sierra 3434 Yamaha Water Pump Repair Kit
• Sierra 3442 Yamaha Water Pump Repair Kit
• Sierra 3371 Yamaha Water Pump Repair Kit
• Sierra 3312 Yamaha Water Pump Repair Kit
• Sierra 33131 Yamaha Water Pump Repair Kit

Related Yamaha Impellers

• Sierra 3042 (18-3042) Yamaha Impeller F75/F80/F90/F100
• Sierra 3074 (18-3074) Yamaha/Mercury/Mariner Impeller 9.915HP
• Sierra 3073 (18-3073) Yamaha/Mercury/Mariner Impeller 45HP
• Sierra Impeller 18-3086 Yamaha Outboard Water Pump Replacement

Always confirm fitment against your Yamaha service manual and full model/year before ordering.