Janome MyLock 744D Instruction Manual

The Janome MyLock 744D is a professional 4-thread overlock sewing machine designed for home and light commercial use. It features differential feed for stretch fabrics, built-in rolled hemming, easy threading system, adjustable stitch length and width, free arm capability, built-in thread cutter, and LED lighting. Below are key sections for safety, features, setup, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation & Setup 3. First-Time Operation 4. Technical Specifications 5. Controls and Settings 6. Stitch Selection 7. Threading Instructions 8. Maintenance & Cleaning 9. Safety Information 10. Troubleshooting

Features at a Glance

Key components: 4-thread overlock capability, Differential Feed System, Built-in Rolled Hem, Free Arm, LED Work Light, Easy Threading Guide.

Feature	Description
Differential Feed	Prevents stretching or puckering on various fabrics
Rolled Hem	Built-in function for professional edge finishing
Stitch Length Control	Adjustable from 1-4mm for different fabric types
Stitch Width Control	Adjustable from 3-7mm for various seam finishes
Free Arm	For sewing sleeves, cuffs, and other tubular items
LED Light	Bright illumination of work area
Thread Cutter	Built-in blade for convenient thread trimming
Tension Dials	Individual controls for upper and lower loopers
Presser Feet	Includes standard and rolled hem feet
Power Switch	On/off control with safety features

Installation & Setup

Unpack and inspect all components. Place on stable, level surface.

Remove packaging materials and protective covers from machine.
Attach free arm extension if removed during shipping.
Connect foot controller to machine and power outlet.
Install needles: Use Janome standard needles, insert with flat side to back.
Thread machine following color-coded threading guide.

WARNING! Keep fingers away from moving parts during operation. Always unplug when not in use.

First-Time Operation

Power on machine; test on scrap fabric first.

Select basic 4-thread overlook stitch for initial testing.
Set stitch length to 2.5mm and width to 5mm for general purpose.
Place fabric under presser foot, lower foot lever.
Press foot controller gently to begin sewing.
Guide fabric through, allowing feed dogs to move material.

CAUTION! Always start with scrap fabric to test settings. Keep work area clean and organized.

Technical Specifications

Machine Type: 4-thread Overlock
Stitch Length: 1-4mm adjustable
Stitch Width: 3-7mm adjustable
Differential Feed Ratio: 0.7-2.0
Speed: Up to 1300 stitches per minute
Needles: Janome standard needles x 2
Threading: Color-coded easy threading system
Lighting: LED work light
Power Requirements: 110V, 60Hz
Weight: 15.4 lbs (7 kg)

Controls and Settings

Main controls located on front and side panels. Stitch length dial, stitch width dial, differential feed control, tension dials.

Front Panel: Stitch Length Dial (1-4), Stitch Width Dial (3-7), Differential Feed Lever (0.7-2.0).

Side Panel: Upper Looper Tension Dial (1-9), Lower Looper Tension Dial (1-9), Needle Thread Tension Dials (1-9). Rolled Hem Lever: Switch between standard and rolled hem stitching. Presser Foot Pressure: Automatic adjustment based on fabric thickness.

Stitch Selection

Four primary stitch types available with variations.

4-thread Overlock: Strong seam for woven fabrics
3-thread Overlock: Lightweight seam for delicate fabrics
Rolled Hem: Narrow hem for lightweight fabrics
Flatlocking: Decorative seam for stretch fabrics

Tip: Always test stitch on scrap fabric of same type before starting project.

Threading Instructions

Follow color-coded threading path for proper operation.

Upper Looper: Follow blue threading path
Lower Looper: Follow green threading path
Right Needle: Follow red threading path
Left Needle: Follow yellow threading path
Ensure threads are properly seated in tension discs
Pull threads under presser foot toward back before starting

WARNING! Always thread with power off. Ensure needles are properly installed and tightened.

Maintenance & Cleaning

Regular maintenance ensures optimal performance and longevity.

Clean lint buildup after each project using brush provided
Oil moving parts monthly with Janome recommended oil
Check needle condition regularly; replace if bent or dull
Wipe exterior with soft, dry cloth
Store with cover when not in use

CAUTION! Unplug machine before cleaning or maintenance. Use only Janome recommended accessories.

Safety Information

Always follow safety guidelines to prevent injury and damage.

Keep fingers away from moving needles and cutting blade
Unplug machine when not in use or during maintenance
Do not operate with damaged cord or foot controller
Keep work area well-lit and organized
Do not use with children or pets nearby
Disconnect power before changing needles or accessories

Troubleshooting

Symptom	Possible Cause	Corrective Action
Thread breaking	Incorrect tension or threading	Re-thread following color codes; adjust tension
Fabric puckering	Incorrect differential feed setting	Adjust differential feed lever; test on scrap
Uneven stitches	Dull needle or incorrect threading	Replace needle; re-thread all positions
Machine not feeding	Presser foot not lowered	Lower presser foot lever completely
No power	Power cord disconnected	Check all connections; ensure power switch on
Loud noise	Lint buildup or need for oiling	Clean and oil machine; check for obstructions

Service: Contact authorized Janome service center for repairs. Warranty: 25-year limited warranty.

Support: Janome America, Inc. 1-800-631-0183 www.janome.com