Official Kenmore Sears Overlock Machine Model No. 385.16644 - Owner's Manual

Kenmore 385.16644 Owner's Manual - 1999 Edition

The Kenmore 385.16644 is a high-performance household overlock system designed for 2, 3, and 4-thread versatility, reaching industrial-grade speeds of 1,300 stitches per minute. A critical operational requirement involves the lubrication of the needle bar and upper looper drive: applying 1-2 drops of high-quality sewing machine oil to these specific friction points every 8-10 hours of use is vital for maintaining mechanical synchronization and preventing thermal expansion of moving parts. This manual serves as the primary technical authority for ensuring long-term equipment reliability and precision stitch formation.

Technical Applicability & Model Range

The engineering standards and maintenance protocols outlined in this documentation apply to the following mechanical configurations:

Kenmore 385 Series Technical Range

• Model 385.16644: Primary overlock unit featuring the 2/3/4D conversion system.
• Drive System Compatibility: Applicable to units utilizing the YC-482P electronic foot controller (110-120V models).
• Sub-variant Coverage: Includes all 385.16644 revisions produced under P/N 788800090.

Operational Parameters & Reliability Proof Points

• Kinematic Efficiency: Engineered to maintain a maximum cycle rate of 1,300 RPM while providing adjustable stitch lengths from 1.0mm to 5.0mm.
• Differential Feed Accuracy: Features a variable ratio of 1:0.5 to 1:2.25, allowing for precise material transport and the elimination of seam puckering on elastic textiles.
• Safety Interlock Systems: Equipped with a primary looper cover safety switch that disables the motor drive when internal components are exposed for threading.
• Needle Calibration: Optimized for HA-1 SP needle systems (#11-#14), ensuring consistent penetration force and minimizing skipped stitches in multi-layered fabrics.

Document Metadata

• Manufacturer: Sears, Roebuck and Co.
• Part Number: 788800090
• Page Count: 114 Pages
• Edition: 1999

Kinematic Depth & Factory Benchmarks

The technical integrity of the 385.16644 is maintained through strict adherence to the following mechanical specifications and calibration limits.

System Architecture & Navigation Aids

Technical navigation is facilitated through detailed exploded-view diagrams identifying 31 critical external and internal components. Section 1 focuses on the primary drive controls, including the pressure adjusting screw and the integrated thread cutter, while Section 2 provides visual mapping for the color-coded threading sequence (Green/Red/Blue/Yellow) essential for tension balancing.

Table of Contents

• Section 1: Know Your Machine – Component identification and standard accessories.
• Section 2: Prepare Your Machine for Sewing – Power connection, needle replacement, and threading.
• Section 3: Learn the Stitches – Tension adjustment, differential feed, and stitch types.
• Section 4: Performance Problems Chart – Diagnostic procedures for mechanical inconsistencies.
• Section 5: Care for Your Machine – Cleaning, lubrication, and blade replacement.

Operational Limits & Maintenance Specifications

• Lubricant Grade: Use only high-purity sewing machine oil; avoid high-viscosity industrial lubricants.
• Knife Alignment: The upper blade must be replaced if the cutting edge becomes dull to prevent fabric fraying; ensure a 0.8mm - 1.5mm overlap with the lower blade.
• Thermal Management: The integrated sewing light is restricted to a 15-Watt maximum bulb to prevent housing deformation.
• Tension Calibration: Standard tension for 4-thread overlocking is factory-set at "3", providing a baseline for secondary adjustments based on fabric weight.
• Needle Position: Always ensure the flat side of the needle faces the rear of the machine during installation to guarantee correct hook timing.

FAQ

Does this manual provide specific applicability for the Kenmore 385 series and its power requirements? Yes, this documentation is specifically authored for the Kenmore Model No. 385.16644 (Overlock 2/3/4D) and confirms the unit is designed exclusively for household use. It details compatibility with electrical systems requiring a specific 15-Watt bulb for the sewing light and utilizes the YC-482P foot controller for precise motor speed regulation.

What are the critical technical specifications for stitch dimensions on the 385.16644 model? The manual defines exact operational limits, including a maximum sewing speed of 1,300 stitches per minute. For technical precision, the stitch length is adjustable between 1 mm and 5 mm, while the standard width for a right-needle overlock is 3.0 mm to 5.0 mm, expanding to 5.0 mm to 7.0 mm when utilizing the left needle.

Is there comprehensive coverage for the internal threading system and blade mechanics? The document provides exhaustive schematics for the color-coded threading paths—specifically the Green, Red, Blue, and Yellow guides located behind the looper cover. Additionally, it details the system architecture for the cutting mechanism, noting that the upper knife is a movable component that can be deactivated or replaced to maintain the integrity of the fabric edge.

What specialized maintenance procedures are required to ensure the longevity of the drive system? Maintenance protocols dictate that the machine must be cleaned and lubricated regularly to prevent lint buildup in the feed dog area. A vital diagnostic insight involves the "Performance Problems Chart" in Section 5, which troubleshooting specific mechanical failures such as needle deflection or thread breakage by verifying the needle position—specifically ensuring the flat side of the HA-1 SP needle faces the back.

How does the digital format of this service manual enhance troubleshooting for urgent repairs? This digital manual provides instant utility by allowing users to navigate directly to the "What to do when" diagnostic section on page 112 for rapid fault isolation. It enables high-resolution viewing of complex diagrams, such as the differential feed ratio settings (ranging from 0.5 to 2.25), and allows for the printing of specific maintenance pages to be used on the workbench without damaging the original document.