Stihl MM55 Tiller Manual

The Stihl MM55 is a versatile, lightweight, and powerful 2-stroke engine tiller designed for small to medium-sized garden beds and soil cultivation. It features a reliable engine, adjustable tilling width and depth, ergonomic handles, and safety features. Below are key sections for safety, features, assembly, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: 2-stroke engine, adjustable tines, depth regulator, ergonomic handlebar, fuel tank, and safety features.

Feature	Description
Engine	2-stroke, air-cooled, reliable starting
Tilling Width	Adjustable (typically 10-16 inches)
Tilling Depth	Adjustable via depth regulator
Handlebar	Ergonomic, foldable for storage
Fuel Tank	Integrated, easy-fill design
Tines	Steel, replaceable, self-sharpening design
Safety Features	Deadman switch, safety guard
Weight	Lightweight for easy maneuverability
Vibration Damping	Reduced vibration handles
Transport Wheels	Optional accessory for easy movement

Assembly & Setup

Unpack and inspect all parts. Assemble on a flat, stable surface.

1. Attach handlebar: Align with mounting points and secure with provided bolts.
2. Install tines: Slide onto shaft and secure with locking pins.
3. Adjust tilling width: Set tine configuration per manual instructions.
4. Attach safety guard: Secure over tines as directed.
5. Add fuel/oil mix: Use recommended 50:1 2-stroke oil/gasoline mixture.

WARNING! Always wear protective gloves during assembly. Ensure all fasteners are tight before operation.

First-Time Operation

Before starting, perform pre-operation checks.

1. Check fuel level: Ensure proper 50:1 mix is in tank.
2. Inspect tines: Ensure they are secure and undamaged.
3. Set depth regulator: Adjust to shallow setting for initial use.
4. Start engine: Set choke, pull starter cord firmly.
5. Warm up: Allow engine to run at idle for 1-2 minutes.
6. Begin tilling: Engage clutch slowly, guide tiller forward.

CAUTION! Clear area of rocks, roots, and debris before tilling. Keep bystanders at a safe distance.

Specifications

• Engine Type: 2-stroke, air-cooled.
• Displacement: Typically 25-30cc (check specific model).
• Fuel: Gasoline with 2-stroke oil (50:1 ratio).
• Tilling Width: Adjustable, 10-16 inches.
• Tilling Depth: Adjustable up to 8 inches.
• Weight: Approximately 20-25 lbs.
• Handlebar: Adjustable, foldable.
• Warranty: Limited warranty, see manual for details.

Controls and Settings

Main controls located on handlebar. Engine controls on engine housing.

Handlebar: Throttle lever, clutch lever, kill switch, depth regulator knob.

Engine: Choke lever, primer bulb (if equipped), fuel valve, starter grip.

Adjustments: Tilling depth (via regulator knob), tilling width (by repositioning tines), handlebar height (loosen bolts, adjust, retighten).

Tilling Operation

For effective soil cultivation.

1. Prepare area: Remove large rocks, debris, mark boundaries.
2. Set depth: Start shallow, increase gradually in subsequent passes.
3. Start engine: Follow starting procedure.
4. Engage tines: Squeeze clutch lever slowly to engage tines.
5. Guide tiller: Walk at steady pace, allowing tines to work.
6. Overlap passes: Overlap slightly for even tilling.
7. For hard soil: Make multiple shallow passes rather than one deep pass.
8. Shut down: Release clutch, allow tines to stop, turn off engine.

Tip: Tilling moist (not wet) soil reduces effort and improves results.

Maintenance Schedule

Regular maintenance ensures longevity and performance.

Interval	Task
Before each use	Check fuel, inspect tines and fasteners, check for damage
Every 10 hours	Clean air filter, check spark plug
Every 25 hours	Replace spark plug, clean cooling fins
Every 50 hours	Change gearbox oil (if applicable), inspect clutch
Seasonally	Full inspection, replace worn tines, lubricate moving parts

Note: Use only genuine Stihl parts for replacement.

Storage & Winterization

Proper storage prevents fuel system issues.

1. Drain fuel: Run engine until tank is empty, or use fuel stabilizer.
2. Clean tiller: Remove dirt, debris from tines and engine.
3. Inspect: Check for wear, damage, address before storage.
4. Store: In dry, covered area, with tines off ground.
5. Protect: Cover to prevent dust accumulation.

CAUTION! Never store with fuel in tank for extended periods without stabilizer.

Safety Information

Always follow safety guidelines to prevent injury.

• Wear safety gear: Gloves, eye protection, sturdy shoes, long pants.
• Clear area: Remove bystanders, especially children and pets.
• Inspect before use: Check for loose parts, damage.
• Operate sober: Never operate under influence of drugs/alcohol.
• Use both hands: Maintain firm grip on handlebar.
• Beware of kickback: Be prepared for sudden movement if tines jam.
• Disconnect spark plug: Before performing any maintenance.

WARNING! Rotating tines can cause severe injury. Keep hands and feet away at all times.

Warranty & Support

Stihl offers a limited warranty for the MM55 Tiller. Proof of purchase required. Warranty covers defects in materials and workmanship under normal use. For support, contact authorized Stihl service dealers or visit www.stihlusa.com. Customer service: 1-800-467-8445.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	No fuel, stale fuel, clogged spark plug	Check fuel level, use fresh mix, clean/replace spark plug.
Engine runs poorly	Dirty air filter, incorrect fuel mix	Clean air filter, ensure proper 50:1 mix.
Tines won't engage	Clutch cable loose, worn clutch	Adjust clutch cable, inspect clutch assembly.
Excessive vibration	Loose tines, damaged tine shaft	Tighten tine fasteners, inspect shaft for damage.
Tiller is hard to control	Depth too deep, tilling hard soil	Reduce tilling depth, make multiple shallow passes.
Tines clog with debris	Wet soil, too much organic matter	Till when soil is drier, clear debris frequently.

For Service: Contact authorized Stihl dealer. Do not attempt major repairs yourself.