Small Engines (Lawn Mowers, etc.): Stihl Trimmer Mod FS 55, 2 stroke engines, fs 55


Question
QUESTION: Unit starts and idles normally. When I open throttle engine bogs down and won't accelerate or get any power. Have changed gas, taken carb apart and took to dealer for inspection. It appears ok.
What else could be cause of this issue.

ANSWER: Could be the carb adjustment. Has anyone removed the muffler, and checked the spark arrest screen behind it, this is common with 2 stroke engines. Give the fuel filter in the tank a good check over. Also check the entire length of plastic fuel line, they tend to dry out crack, and break. Last, check that the fuel cap vent is working properly.

         Tom

---------- FOLLOW-UP ----------

QUESTION: Thanks for the tips. I removed the muffler and unit runs normally. The muffler, spark arrestor is a sealed unit. How can I clean it.

Answer
It may not be a type that can be cleaned. You will have to replace the muffler. Another word of advice, use a good oil from now on, like a ashless oil that leaves very little carbon build up, and this won't happen in the future, also make sure your mixing the oil to the correct ratio........Please be so kind as to leave me a rating I always appreciate it......Thanks, Tom