To change the impeller on a Johnson outboard marine pump, first disconnect the lower unit and remove the water pump housing. Carefully extract the old impeller and replace it with a new one, ensuring proper alignment. Reassemble the pump housing and lower unit, then test for proper water circulation.

Size: Typically ranges from 2.5 to 4 inches in diameter, depending on the pump model.

Grade: Standard marine-grade impellers designed for freshwater and saltwater use.

Viscosity: Compatible with lubricants and fluids with viscosities ranging from 10W-30 to 90W gear oil.

Buoyancy: Not applicable, as impellers are submerged and non-buoyant.

Material: Nitrile rubber (NBR) or neoprene for durability and resistance to water, oil, and corrosion.

Rotation: Clockwise or counterclockwise, depending on pump design.

Blade Count: Typically 6 to 12 blades for optimal water flow.

Operating Temperature: -20°F to 180°F (-29°C to 82°C).

Pressure Rating: Designed for low to moderate pressure systems (10-50 psi).

Compatibility: Fits Johnson Outboard marine pumps and similar OEM replacements.