Description
Overview:
The Ring Set O/S 30 for JAP 4/3 Engines is a genuine JAP piston ring set for restoring correct compression and sealing in vintage JAP single-cylinder engines. Manufactured from durable, wear‐resistant metal and finished to precise tolerances, the rings help maintain power, starting, and fuel efficiency by sealing the combustion chamber and controlling oil. This set is the +0.030 in oversize (+0.76 mm), ideal for use after a rebore to factory specifications. Suited to JAP 4/3 and 43 engines, it keeps period machinery running reliably while preserving originality. Supplied as unused old stock, the parts may show light tarnish from storage, but remain fully serviceable and fit for purpose when installed to standard engine-building practices.
Key Features:
- Genuine JAP part for assured fit and compatibility on 4/3 and 43 engines
- Oversize +0.030 in (+0.76 mm) to suit rebored cylinders and restore compression
- Precision-made ring faces and consistent radial tension for reliable sealing
- Heat- and wear-resistant construction for long service life in demanding use
- Matches original specifications to maintain authentic performance and feel
- Helps improve starting, power delivery, and oil control in vintage engines
- Straightforward to fit with standard tools; check end gap and ring orientation
- Unused old stock; cosmetic ageing only and functionally sound when installed correctly
Typical Applications:
Used during rebuilds and overhauls of JAP 4/3 and 43 engines fitted to vintage construction, agricultural, and garden equipment. Common on stationary or industrial machines such as generators, pumps, mixers, compactors, and cultivators, where reliable compression and oil control are essential for smooth running and consistent output.
Also known as:
Piston ring set (oversize +0.030 in / +0.76 mm), 30‐thou oversize rings, JAP 4/3 oversize piston rings, JAP 43 ring set, oversize ring pack for JAP engines, R7620 +030 rings, vintage JAP piston rings, replacement rings for rebored JAP cylinders.
Fits Models:
4/3, 43, JAP 4, JAP4
Alternate Part Numbers:
R7620 + 030
Product Specifications
| L&S Part No. | JAP43RS30 |
|---|---|
| Part Type | Genuine Part |
| Manufacturer | JAP |
| Unit of Sale | 1 |
| Machine Type | Engines |
| Fits Brands | JAP |
| Key Features | - Genuine JAP part for 4/3 and 43 engines - Oversize +0.030 in for rebored cylinders - Precision-made for reliable sealing and compression - Heat- and wear-resistant for long service life - Matches original specifications for authentic performance |
| Fits Models | JAP 4, 3 |
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