Rotary 3658 Fuel Pump Diaphragm for Tillotson HS Series Carburetors

The Rotary 3658 is a replacement fuel pump diaphragm engineered for use with Tillotson HS Series carburetors. This aftermarket diaphragm is manufactured to match the original specifications of Tillotson OEM part 237-144, providing a reliable and cost-effective repair solution for small engine equipment.

The fuel pump diaphragm plays a critical role in the carburetor's fuel delivery system, flexing in response to crankcase pressure pulses to draw fuel from the tank and deliver it to the carburetor. A worn or cracked diaphragm results in hard starting, rough running, or a complete failure to run — making timely replacement essential for proper engine operation.

Key Features:

• Direct replacement for Tillotson 237-144 fuel pump diaphragm
• Fits Tillotson HS Series carburetors
• Also available as part of the DG-5HS carburetor diaphragm kit
• Manufactured to OEM specifications for correct fit and function
• Suitable for chainsaws, trimmers, and other small engine outdoor power equipment

Cross-reference part number: Tillotson 237-144. This diaphragm is also included in the Rotary DG-5HS kit for a complete carburetor rebuild.