Can not start my stihl fs 66 weed eater. I have tried to adjust both the ''H'' and ''L'' carburator screws and I still can not start the machine. Do you have a solution to problem?
Turn both screws CW to stops (lightly), then back out CCW 1-3/4 turns each. This a basic setting and both will need to be set leaner (CW) after the engine warms up. Remove the spark plug and check for blue sparks when the engine is pulled through. If nothing, try a new spark plug. If still nothing, try removing the stop switch connection at the ignition module and retry for sparks. If nothing again, replace the ignition module. Use a thin business card to set the pole gap (the magnets should be under the poles of the ignition module) when installing the replacement. If you get sparks in the first test, try spraying some carburetor cleaner in the plug hole, replace the plug, and attempt to start. If you get a pop or two, then you have fuel problems. Check the fuel lines for condition, check the filter inside the fuel tank for plugging, and tightness of the carburetor screws and nuts. Remove the muffler and check for plugging. Check the air cleaner for plugging. If it still won't run, then the carburetor should be removed, disassembled, cleaned, and fresh gaskets and diaphragms installed. Keep track of what went where as you remove parts. If the machine appears to have good compression, it should start. When the engine is warmed up, adjust the H needle to 4-stroke at high speed, but smooth out when cutting. The L needle should be adjusted to allow the engine to run fairly smoothly, but allow the engine to 'follow the throttle'. Idle speed should be set so that the string head does not turn, but keeps the engine running. Hope some of this will get you trimming again!
6,450 views
Usually answered in minutes!
×