Voltage regulator replacement compatible with Briggs and Stratton part numbers 4457770231E1 and 845907. Designed for small engine charging systems, this regulator restores stable voltage output, helping electrical systems perform reliably. Key benefits Restores proper charging: Regulates alternator output to maintain correct battery charge and reduce starting and running issues. Protects electrical components: Prevents overcharging or undercharging that can damage batteries, lights, and ignition components. Directfit replacement: Matches the original regulator form and mounting for straightforward installation and reliable connection. Reliable performance: Designed for consistent voltage regulation under normal small engine operating conditions. What it does Controls and stabilizes the charging voltage produced by the magneto or alternator so the battery and electrical system receive steady voltage during operation. Replaces failed or intermittent regulators that cause dim lights, dead batteries, or erratic engine performance. Compatibility and fit Compatible with small engines that use part numbers 4457770231E1 and 845907. Intended as a replacement for the specified regulator part numbers; confirm part number match before installation. Practical attributes Function: Voltage regulation for small engine charging systems. Compatibility: Fits engines and equipment calling for part numbers 4457770231E1 or 845907. Design: Compact directfit form factor for original mounting points and connector types. Performance: Provides steady voltage regulation to support reliable starting and electrical operation. Installation notes the regulator with the engine off and battery disconnected. Install using the same mounting points and electrical connections as the original regulator. Verify connector type and part number match to ensure compatibility. Use scenarios Lawn tractor : a failed regulator on a riding mower that uses part number 4457770231E1 to restore charging and lighting function. Portable generator maintenance: Swap in a directfit regulator when the generator battery is not charging or output voltage is unstable. Small engine equipment service: garden tractors, pressure washers, or other outdoor power equipment that list part number 845907 as the required regulator. Notes Confirm the engine or equipment lists part number 4457770231E1 or 845907 before ordering to ensure correct fit.