Restore the engine performance of your heavy-duty chainsaw with the STIHL Service Kit . This genuine maintenance set is specifically designed for the early-series STIHL MS 311 and MS 391 models. Regular servicing is essential for protecting your engine from the fine dust and debris generated during large-scale felling and bucking tasks, ensuring your saw starts reliably and runs at full power.
The STIHL Service Kit provides a specialized dual-stage filtration solution for these high-torque engines. It includes a Pre-Air Filter, a Main Air Filter, and a matched Spark Plug. By replacing the complete filtration system as a set, you ensure optimal air intake and prevent "starving" the engine of the oxygen it needs to maintain high RPMs under heavy load.
Compatibility Note: This kit (Part # 1140 007 1800) is specifically for older MS 311 models (Serial No. lower than 295 938 526) and older MS 391 models (Serial No. lower than 295 938 026).
What’s Included in Service Kit 40
Dual-Stage Air Filtration (1140 120 1600)
- Pre-Air Filter: Acts as the first line of defense, capturing larger wood chips and coarse debris before they reach the main filter.
- Main Air Filter: Features specialized media to trap micro-fine dust, protecting the carburetor and cylinder from internal scoring and wear.
- Optimized Airflow: The dual-layer design allows for higher dust holding capacity, meaning you can work longer between filter cleanings.
Genuine Fuel Pick-Up Filter (0000 350 3504)
- Precision Screening: Filters out contaminants and moisture from the fuel tank, protecting the high-performance carburetor used in the 300-series saws.
- Consistent Fuel Supply: Ensures a clean, steady flow of fuel to maintain engine stability during long, vertical cuts in large timber.
NGK BPMR7A Resistor Spark Plug
- Professional Grade: Provides the strong, consistent spark required for the larger displacement cylinders of the MS 311 and MS 391.
- Cold-Start Reliability: Engineered to provide easy starting in varied weather conditions, from cold winter logging to hot summer clearing.
- EMI Protection: Includes an internal resistor to prevent electrical interference with the saw’s ignition module.
Technical Specifications & Compatibility
| STIHL Kit Number | Service Kit (1140 007 1800) |
| Compatible Models | MS 311 (with Serial No. lower than 295 938 526) MS 391 (with Serial No. lower than 295 938 026) (Early Series) |
| Filter Configuration | Pre-Filter & Main Filter System |
| Spark Plug Gap | 0.020" (0.5 mm) |