Proline® performance 49mm cylinder and piston kit for Stihl 039 and MS390 chainsaws, and a big bore upgrade for 029, MS290, and MS310 models. Please compare your existing parts with our pictures before ordering to verify proper fitment. Actual pictures shown. Cylinder color may vary from the pictures; color variation does not affect fitment or performance. Parts are not made in China.
⚠️ IMPORTANT INSTALLATION NOTES:
1. Cylinder Mounting Screws: This cylinder has machine-threaded mounting holes. Two installation options are available:
- Use the included machine screws: Threadlocker is highly recommended when installing the included screws.
- Use self-tapping screws: You may reuse your original OEM self-tapping screws if they are in good condition or use new self-tapping screws. These screws will cut through/override the existing machine threads during installation.
2. 2019 Models – Muffler Fitment: The muffler bolt slots MUST be filed larger to achieve proper fitment.
Includes:
- Cylinder
- Piston
- Piston rings
- Circlips
- Wrist pin
- Screw (4pcs)
Specs:
- 49mm
- Proline® Performance Series
- Nikasil plated
- Decompression valve port: Yes (valve or plug not included; sold separately)
-
Requires silicone sealant for assembly. We recommend Dirko HT
Replaces Stihl OEM #:
- 1127 020 1216, 11270201216