Description
Overview:
This Cylinder Base Nut is a Genuine JAP component for the JAP 4/3 engine, used to secure the cylinder barrel to the crankcase studs and maintain sealing and alignment under engine vibration. Manufactured from durable metal for long service life, it is an original equipment part carrying OEM No. 284 for assured compatibility and fit. It is well suited to owners, restorers, and mechanics working on vintage JAP stationary engines where authenticity and reliability matter. As unused old stock, it may show light age-related tarnish that does not affect function. Designed for the JAP 4/3 and compatible with JAP 4 variants, it helps preserve the integrity of rebuilds and routine maintenance on classic equipment.
Key Features:
- Genuine JAP part for authenticity and correct fit (OEM No. 284)
- Made from durable metal to withstand heat, vibration, and repeated torque cycles
- Factory-appropriate dimensions for reliable seating on the cylinder base studs
- Helps maintain compression and gasket sealing at the cylinder-to-crankcase joint
- Suitable replacement for worn, rounded, or missing original hardware
- Unused old stock; minor tarnish possible but performance unaffected
- Supports faithful restorations by keeping original specification hardware
- Straightforward installation using standard workshop hand tools
Typical Applications:
Used during engine rebuilds, barrel refits, gasket changes, and routine maintenance on JAP 4/3 engines. Ideal when replacing damaged or mismatched fasteners to restore correct clamping force and prevent leaks, vibration loosening, or misalignment in vintage stationary engine assemblies.
Also known as:
Barrel retaining nut, cylinder foot nut, crankcase-to-barrel fastener, base fixing fastener, stud nut (cylinder base), barrel clamp nut, cylinder base fixing fastener.
Fits Models:
4/3 Engine, JAP 4, JAP4
Alternate Part Numbers:
284
Product Specifications
| L&S Part No. | 284 |
|---|---|
| Part Type | Genuine Part |
| Manufacturer | JAP |
| OEM No. | 284 |
| Unit of Sale | 1 |
| Applications | 4/3 Engine, JAP 4, JAP4 |
| Machine Type | Engines |
| Fits Brands | JAP |
| Fits Models | JAP 4, 3 |
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