Bosch 9786 Spark Plug

Reliable Ignition Performance for Mini Cooper Models

The Bosch OE Fine Wire Iridium spark plug 9786 is engineered to deliver consistent ignition performance for Mini Cooper, Cooper Countryman, and Cooper Paceman vehicles. Designed with advanced materials and precise specifications, this spark plug supports efficient combustion and engine reliability.

• Iridium center electrode tip for enhanced durability and ignition
• Copper core in both center and ground electrodes for optimal conductivity
• Standard ground electrode tip with platinum material for wear resistance
• J-gap ground configuration with a single ground electrode
• Non-removable nut electrical terminal type for secure connection
• Flat seat type with a 14 mm bi-hex hex size for proper fitment
• Pre-gap size of 0.8 mm and a reach of 26.5 mm
• Ceramic insulator with projected design for heat management
• Resistor type spark plug with 6000 ohms resistance to reduce electrical noise
• Manufacturer heat range rating of 5 suitable for specified Mini models

About the Bosch OE Fine Wire Iridium Product Line

The OE Fine Wire Iridium line from Bosch focuses on precision-engineered spark plugs that utilize fine wire iridium tips to improve ignition efficiency and longevity. This product line is designed to meet or exceed original equipment specifications, providing reliable performance and durability for vehicles like the Mini Cooper series. The fine wire design reduces voltage requirements and enhances spark consistency, contributing to smoother engine operation.

Detailed Product Description

The Bosch 9786 spark plug features a fine wire iridium center electrode tip paired with a copper core, which ensures excellent electrical conductivity and durability. The ground electrode uses a platinum tip and copper core, arranged in a J-gap configuration with a single electrode to optimize spark exposure and combustion. The ceramic insulator with a projected design helps manage heat effectively, while the resistor built into the plug reduces electromagnetic interference. With a flat seat and a 14 mm bi-hex hex size, this spark plug fits securely in the engine cylinder head. The 0.8 mm pre-gap and 26.5 mm reach are calibrated to maintain proper spark gap and combustion chamber positioning, supporting efficient engine performance in Mini Cooper, Cooper Countryman, and Cooper Paceman models.

Common Applications and Issues Addressed

• Replacement for worn or fouled spark plugs in Mini Cooper vehicles
• Improves ignition reliability and reduces misfires
• Helps restore engine power and fuel efficiency
• Reduces electrical noise interference affecting vehicle electronics
• Supports consistent engine starting and smooth idling

Installation Notes and Tips

Ensure the spark plug gap is set to the specified 0.8 mm pre-gap before installation. Use a torque wrench to tighten the spark plug to the manufacturer’s recommended torque to avoid damage to the flat seat or cylinder head. The 14 mm bi-hex hex size allows for proper tool engagement. Avoid over-tightening to prevent thread damage. This spark plug is designed for 4-cycle engines and is compatible with Mini Cooper, Cooper Countryman, and Cooper Paceman models.

Quality Assurance and Warranty

Bosch OE Fine Wire Iridium spark plugs are manufactured to meet strict quality standards and original equipment specifications. The use of high-grade materials such as iridium and platinum ensures durability and consistent performance. While specific warranty details are not provided here, Bosch products typically come with manufacturer-backed quality assurance to support reliability in automotive ignition systems.