The STIHL MM55 is a multi-task power tool designed for various yard maintenance applications. This parts manual provides detailed information on components, assembly, maintenance, and ordering of genuine STIHL replacement parts. Below are key sections covering identification, engine components, cutting systems, safety features, maintenance procedures, and parts ordering.
Key identification features: Model plate location, engine specifications, serial number location, and general configuration.
| Component | Description |
|---|---|
| Model Designation | STIHL MM55 MultiTask System Power Tool |
| Engine Type | 2-stroke, single cylinder, air-cooled |
| Displacement | 27.2 cm³ (1.66 cu. in.) |
| Powerhead Weight | Approximately 5.1 kg (11.2 lbs) |
| Fuel/Oil Mix | 50:1 (STIHL HP Ultra oil recommended) |
| Serial Number Location | Stamped on crankcase near muffler |
| Attachments | Accepts MM series trimmer, edger, cultivator, etc. |
| Safety Certifications | Meets ANSI B175.3 and EPA standards |
| Warranty Period | Limited warranty as per STIHL policy |
| Manufacture Date Code | Located on model plate (YY/WW format) |
Complete breakdown of engine assembly parts including crankcase, cylinder, piston, and related components.
WARNING! Engine components are precision parts. Use proper tools and torque specifications during assembly/disassembly.
Parts for various cutting attachments including trimmer head, brush cutter blade, and edger blade.
CAUTION! Always use STIHL-approved cutting attachments. Ensure blade is properly balanced and secured before operation.
Complete fuel system parts including tank, carburetor, fuel lines, and filter.
Fuel Tank: Polyethylene tank, cap, vent, and mounting points. Carburetor: Zama C1Q series, includes diaphragm, gaskets, jets, and adjustment screws. Fuel Lines: Supply and return lines with clamps. Fuel Filter: In-tank filter element. Primer Bulb: Primer assembly and check valves.
Ignition module, spark plug, wiring, and stop switch components.
Tip: Always use genuine STIHL ignition parts to ensure proper timing and performance.
Air filtration and engine cooling components.
WARNING! Never operate engine without air filter or cooling shroud installed.
Drive system components transmitting power from engine to attachment.
Drive Shaft: Flexible shaft, couplings, and support bearings. Gearbox: Bevel gear set, housing, output shaft, and seals. Lubrication: Gearbox grease (STIHL Grease 10 or equivalent). Seals: Shaft seals and gaskets preventing lubricant leakage.
Safety components including guards, shields, and protective equipment.
CAUTION! Always replace damaged safety components before operating equipment.
Recommended maintenance intervals and procedures.
Daily: Check for loose fasteners, clean exterior, inspect cutting attachment. Every 10 Hours: Clean air filter, check spark plug. Every 25 Hours: Clean spark arrestor, check fuel filter. Every 50 Hours: Clean cooling system, check drive shaft. Every 100 Hours: Replace fuel lines, clean carburetor, check gearbox grease. Seasonal: Empty fuel system for storage, sharpen/replace cutting blades.
| Component Group | Part Number Prefix | Ordering Information |
|---|---|---|
| Engine Assembly | 1128 | Reference serial number for exact parts |
| Cutting Attachments | 4132 | Specify attachment type when ordering |
| Fuel System | 1129 | Include carburetor model number |
| Ignition System | 1131 | Provide engine serial number |
| Controls & Handles | 4220 | Specify handle type (loop/D-handle) |
Exploded Views: Available through STIHL dealers or online parts diagrams.
Service: Contact authorized STIHL servicing dealer for parts and service. Visit www.stihlusa.com for dealer locator and technical information.