Performance Muffler Cover – Fits Stihl 066/660/650

Aerospace-Grade Performance Exhaust System for STIHL 066/660/650

Enhance power and improve engine cooling with this precision-engineered exhaust system designed for the STIHL 066/660/650 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:
STIHL 066, 660, and 650

Includes:

• One-piece muffler cover CNC machined from 6061 T6 billet aluminum
• Spark arrestor screen with aperture size compliant with USFS specifications
• Longer stainless steel 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 9.01% increase in horsepower, and a 10.53% 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 is required for optimal performance

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