Flexible Rubber Water Pump Impeller 1210-0001 – 12 Blade Neoprene 57 mm 12-Spline – Fits Johnson 09-1027B

How to Match This Part

This is a flexible rubber raw water pump impeller. It sits inside the pump housing behind the cover plate and is driven by a 12-tooth splined shaft. It replaces the primary original part number Jabsco 1210-0001, and is also supplied against Johnson 08-1027B / 09-1027B, JMP 7100-01, DJ 08-21-1201 and Yanmar 129470-42530.

Match this part by checking your engine in this order:
1. Original impeller part number (stamped on the old impeller or listed in the pump section of your parts catalog)
2. Drive type (this listing is a 12-spline hub, not a key drive and not a pin drive)
3. Pump model (cast or labelled on the pump body)
4. Engine or generator model code (on the identification plate)

Identify it physically before ordering. This impeller has twelve vanes moulded in black neoprene around a machined brass 12-spline insert. JMP 7100-01 is 57 mm diameter, 31.5 mm width and 16 mm (5/8 in.) bore. It is not interchangeable with the 12-blade key-drive JMP 7110-01 (57 × 20 × 12.7 mm) or with nitrile Jabsco 1210-0003.

• ✓ Primary OEM: Jabsco 1210-0001
• ✓ Product form: 12-blade neoprene impeller, brass 12-spline insert, 16 mm bore
• ✓ Fitment: part number, then drive type, then pump model

Part Number Cross-Reference

Use this table to confirm equivalent part numbers. Jabsco 1210-0001-P and JMP 7100-01K are kit numbers. This listing is the impeller only.

Compatible Engine Models

Confirm the original impeller number and the 12-spline hub. Do not assume every Yanmar 3JH / 4JH or Volvo Penta D2 uses this part. Match the original number first.

Technical Specifications

Package Contents

This listing is for the impeller only, as shown in the product images. Please refer to the part number cross-reference table to confirm component details.

Cover plate gaskets, O-rings and lubricant are not included. Jabsco 1210-0001-P and JMP 7100-01K add those service parts. If your service procedure calls for a new cover seal, order it separately against your pump model.

Installation Guide

1. 1 Stop the engine, let it cool, and close the raw water seacock so water cannot enter the boat while the pump is open.
2. 2 Remove the cover plate screws and lift off the cover. Keep the screws and the old gasket or O-ring together so you can compare the seal size when reassembling.
3. 3 Note the spline orientation, then grip the brass insert and pull the old impeller straight off. Recover any broken vane pieces from the downstream cooling circuit before continuing.
4. 4 Clean the housing bore and the wear plate, and inspect them for scoring. Apply a marine-grade impeller lubricant, glycerine or soapy water to the bore and the new vanes. Do not use petroleum-based grease, which attacks neoprene.
5. 5 Align the 12-tooth spline in the brass insert with the pump shaft, then press the impeller in while turning the shaft in the normal direction of rotation so all twelve vanes lay over the same way.
6. 6 Refit the cover plate with a serviceable gasket or O-ring, tighten the screws evenly in a crisscross pattern, open the seacock, then start the engine and confirm a solid stream of cooling water and no leaks at the cover.

Note: Professional installation is recommended to ensure safety and optimal performance.

Troubleshooting & FAQ

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist, even if your model is listed, do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• The impeller is supplied on its own. Cover seals and lubricant must be ordered separately if your service procedure requires them.
• This is a 12-spline, 16 mm bore impeller. It will not fit the 12-blade key-drive JMP 7110-01 (12.7 mm) or nitrile 1210-0003.
• Never run the pump dry. Even a few seconds without water will damage the neoprene vanes.
• Professional installation is recommended to ensure safety and optimal performance.

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