Description
Overview:
This genuine Husqvarna valve (OEM 503 66 54-01) is a precision screw-in component used on Husqvarna petrol machines, primarily chainsaws such as the 246 and 340. Built from durable machined metal to withstand heat, vibration and fuel exposure, it regulates cylinder pressure during starting to help the engine turn over smoothly and protect the recoil system. Once running, it seals reliably to maintain proper compression. Designed for a direct replacement on compatible Husqvarna models, it restores correct operation when the original valve has become worn, stuck or leaking. Genuine Part status ensures the correct fit, materials and performance expected by professional users and DIY owners who need dependable starting and consistent cutting power.
Key Features:
- Genuine Husqvarna part for assured compatibility and quality (OEM 503 66 54-01)
- Precision-engineered metal body for strength and long service life
- Helps reduce pull-start effort and strain on starter ropes and pawls
- Positive sealing under running conditions to maintain engine compression
- Direct screw-in replacement on listed models; straightforward to fit with basic tools
- Stable performance in demanding forestry, arborist and grounds-care use
- Reliable under heat, vibration and fuels typically used in 2‐stroke engines
- Supports safe, predictable starting behaviour across the compatible range
Typical Applications:
Replacement for a worn or leaking starting valve on Husqvarna chainsaws and selected compatible machines. Commonly fitted during servicing to resolve hard starting, kick-back on the pull cord, loss of compression, or irregular idle. Suitable for professional forestry and arboriculture, landscaping, hire fleets, estate maintenance, and domestic firewood cutting.
Also known as:
Decompression valve, decomp valve, compression release valve, starting valve, pressure relief valve (chainsaw), cylinder head valve for Husqvarna engines.
Fits Models:
246, 335R, 340, 340E, 343F, 343FR, 343FRM, 343R, 345, 345E, 345FX, 345FXT, 345R, 345RX, 346XP, 350, 351, 353, 42, 51, 55, 55 Rancher
Alternate Part Numbers:
503 66 54-01, 503665401
Product Specifications
| L&S Part No. | 503 66 54 01 |
|---|---|
| Part Type | Genuine Part |
| Manufacturer | Husqvarna |
| OEM No. | 503665401 |
| Unit of Sale | 1 |
| Fits Brands | Husqvarna |
| Key Features | - Genuine Husqvarna part ensures compatibility (OEM 503 66 54-01) - Precision-engineered metal body for durability - Reduces pull-start effort and starter strain - Positive sealing maintains engine compression - Direct screw-in replacement for listed models |
| Fits Models | 340 | 246 | 340E | 345 | 345E | 346XP | 350 | 351 | 353 | 42 | 51 | 55 | 55 RANCHER | 335R | 343F | 343FR | 343R | 345FX | 345FXT | 345R | 345RX | 343FRM |
