Professionally compatible with the return springs and accessories for the starter springs of the STIHL chainsaws MS660/MS650/066.

Are you experiencing problems with the starter on your large-displacement STIHL chainsaw, such as a broken recoil spring, insufficient recoil force, or unusual noises when starting? This is usually due to a broken or worn internal recoil spring. This high-quality recoil spring was specially developed for large chainsaws like the STIHL 066, MS660, and MS650 and ensures that your starter functions perfectly again. How the recoil spring works: The recoil spring (also called a mechanical spring) is the central component of the starter pulley. When the rope is pulled, the spring gradually builds up tension and stores energy. When the rope is released, the spring releases this energy, and the rope retracts automatically. If the spring is broken or has lost its elasticity, the starter will no longer function correctly. Key features: High-quality spring steel: Made from high-carbon 65Mn spring steel or an equivalent material, it offers excellent strength and high fatigue resistance. It withstands the considerable shock force during starting, which is generated by the high compression ratio of a large-displacement chainsaw. Precision mechanical design: Wire diameter, outer diameter, number of coils, and spring tension are precisely calculated to ensure a smooth and stable return force during starting. The spring is neither too loose, preventing the rope from retracting, nor too tight, making starting difficult. Reinforced ends: The spring's inner and outer attachment points are subject to particular stress. This product benefits from special reinforcement in these areas, significantly reducing the risk of breakage. Specifications: Accessory name: Starter spring / Return spring / Mechanical spring. Compatible models: STIHL 066, STIHL MS660, STIHL MS650, STIHL MS640, STIHL 064, STIHL 084, STIHL MS880 (some starter versions).