Product Overview The Grundig Spark Plug Tester is a precision diagnostic tool designed to evaluate the performance and aging condition of spark plugs under various operating scenarios. It helps ensure engine safety and efficiency across tractors, vintage cars, RVs, and other gasoline-powered vehicles. Key Features Adjustable Frequency: Simulates different engine speeds (1000–5000 rpm) to check spark plug behavior under various conditions. Improved Spark Detection Station: Spark hole positioned away from adjustment knob for safer and easier operation. Triple Indicator Lights: Accurately distinguish whether spark issues are caused by the tester or the spark plug. Spark Plug Quality & Aging Check: Bright purple spark = good performance Intermittent or weak red spark = aging or defective spark plug Universal Compatibility: Suitable for different spark plug brands and specifications. Stable Power Supply: European standard adapter included for consistent performance and long-lasting durability. How It Works In an engine’s ignition system, the coil generates high voltage (10,000V+), which the spark plug channels into the combustion chamber. The tester evaluates spark intensity and consistency, helping identify faulty spark plugs that could cause misfires, rough idling, or reduced fuel efficiency. Usage Instructions Insert the spark plug into hole 1 or 2 of the tester. (Insert new plug in hole 1 and old plug in hole 2 for comparison). Connect the power supply. Turn key switch clockwise to start tester at 1000 rpm. Indicator light turns on. Rotate further to adjust between 1000–5000 rpm for testing at different frequencies. Precautions Always switch off power before inserting or removing spark plugs. Do not touch plugs during operation (high-voltage risk). Higher frequency = stronger spark intensity. Specifications Product: Spark Plug Tester Compatible with: Tractors, vintage cars, RVs, gasoline engines Power Supply: Standard EU adapter Safety: High-voltage tester, tested before shipment Included: Tester unit + EU adapter