Performance Muffler Cover – Fits Stihl 400.1

Aerospace Grade Performance Exhaust System for the new STIHL MS 400.1

Enhance power and improve engine cooling with this precision engineered exhaust system designed for the STIHL MS 400.1. Made from lightweight 6061 T6 billet aluminum, a high strength aerospace alloy known for excellent heat dissipation, the one piece muffler cover optimizes exhaust flow while helping to keep your engine cooler and extend component life.

Proudly manufactured in the USA and backed by a lifetime warranty, this exhaust system delivers lasting durability under demanding conditions.

Outlet Direction (Facing Bar or Facing Recoil)
Facing Bar means the exhaust outlet points toward the guide bar side of the saw. Facing Recoil means it points toward the pull start side. This is strictly operator preference and has no effect on performance.

Compatible Models
MS 400.1 & MS 363 

Includes

• One piece muffler cover CNC machined from 6061 T6 billet aluminum
• Stainless Steel Intermediate Plate
• Spark arrestor screen with aperture size compliant with USFS specifications
• High Temperature Gasket Made in the USA
• Longer top screws with vibration resistant Belleville washers

Dyno Proven Performance
Tested on a completely stock saw with no modifications other than the muffler cover. Results showed a 7.82% increase in horsepower and a 6.5% increase in torque.
Performance gains will vary depending on the saw and the level of modification.

Installation Notes

• Apply thread locker on all mounting screws for secure, vibration resistant assembly
• Post installation tuning or recalibration is required for optimal performance

Warranty
Lifetime warranty covers defects in materials and workmanship under normal use. Excludes misuse, neglect, or unauthorized modifications.