Perkins M90 Engine Overhaul Kit

Our most comprehensive aftermarket overhaul kit for naturally aspirated Perkins M90 marine engines with build codes beginning 236 or LD. This kit contains the major components required for a complete engine rebuild, including pistons, liners, bearings, gaskets, seals and associated hardware. Kit includes:

• Cylinder liners ×4 (slip-fit, pre-finished and honed)
• 5-ring flat bowl pistons ×4
• Piston ring sets ×4
• Gudgeon (wrist) pins ×4
• Gudgeon pin circlips ×8
• Small end bushes ×4
• Connecting rod bearing set (4 pairs)
• Main bearing set (5 pairs)
• Thrust washer set
• Camshaft bush ×1
• Connecting rod bolts and nuts ×8
• Core plugs ×16
• Complete top gasket set, including:
  • Valve stem seals
  • Injector copper washers
  • Nitrile rubber rocker cover gasket
• Cylinder head gasket with silicone water jacket sealing
• Complete bottom gasket set suitable for both sump pan variations
• Front and rear crankshaft oil seals (includes both early rope seal and later lip seal)
• Lucas Assembly Lubricant (UK orders only)

Important – Cylinder Liners

The Perkins M90 engine was manufactured with three different cylinder liner designs.

This overhaul kit is supplied with the liner option selected when ordering. Before purchasing, remove one existing liner from your engine to confirm the correct type, as identification is difficult while the liner remains installed.

Available liner options:

Option 1

• Plain parallel press-fit liner
• Requires machining (boring and honing) after installation
• Outside diameter: 103.2 mm (4.062")

Option 2

• Flanged, pre-finished liner
• Outside diameter: 103.2 mm (4.062")

Option 3

• Flanged, pre-finished liner
• Outside diameter: 104.2 mm (4.102")

Please refer to the product images to help identify your existing liner.

Standard Crankshaft Journal Sizes

Main bearing journals

• 2.9984" – 2.9992"

Connecting rod journals

• 2.4988" – 2.4996"

These dimensions can be used to determine the correct bearing size if purchasing replacement bearings separately.

Additional Information

• This kit is intended for naturally aspirated Perkins M90 engines with build codes beginning 236 or LD.
• It is not suitable for gas engines with build codes beginning LE.
• Worldwide shipping available.