Stihl KM 55 Instruction Manual
![Stihl KM 55 manual cover](/images/3bc8354f69a8cd148e4a3735/thumbs/thumb175x175.webp)
To start the Stihl KM 55 engine, ensure the engine switch is in the "On" position, set the choke lever to "Cold Start" if the engine is cold, press the fuel pump bulb at least five times, and pull the starter rope until the engine fires. Then, set the choke lever to "Run" and pull the starter rope again until the engine starts.
If the KM 55 engine won't start, check the fuel level and quality, ensure the spark plug is clean and properly connected, verify the air filter is not clogged, and ensure the engine switch is turned on. If problems persist, consult the user manual or contact a service professional.
Regular maintenance should be performed after every 25 hours of operation. This includes cleaning the air filter, checking the spark plug, and inspecting the fuel system for leaks. Annually, or after 100 hours, replace the air filter, fuel filter, and spark plug.
The Stihl KM 55 requires a 50:1 fuel mixture, which is 50 parts gasoline to 1 part 2-stroke engine oil. Always use fresh, high-quality gasoline with a minimum octane rating of 89.
To replace the trimmer line, remove the spool from the trimmer head, cut a length of line approximately 15 feet long, and wind it evenly onto the spool. Secure the line ends in the designated slots, reattach the spool, and ensure it is fastened securely.
For power loss issues, check the air filter for dirt and clean it if necessary, inspect the spark plug for wear or damage, verify the fuel quality, and ensure the exhaust is not blocked. Clean or replace parts as needed.
Engine overheating can be due to a clogged air filter, incorrect fuel mixture, or blocked cooling fins. Clean the air filter, ensure the correct fuel mixture, and inspect the cooling fins for debris.
Excessive vibration may be caused by imbalanced attachments or worn parts. Check that attachments are installed correctly and inspect for any wear or damage. Tighten any loose bolts and replace worn parts as necessary.
If the KM 55 stalls, check the fuel level and quality, inspect the spark plug for fouling, and ensure the air filter is clean. Adjust the carburetor settings if necessary and consult the user manual for guidance.
To clean the air filter, remove it from the engine, wash it in a warm, soapy water solution, rinse thoroughly, and allow it to dry completely before reinstalling. Replace the air filter if it is damaged or excessively dirty.