TROUBLESHOOTING   Chainsaw troubleshooting chart   The different faults that can occur on the chainsaw are   divided into four groups as follows.  Within  each  group   possible operating faults are listed to the left while the   probable fault alternatives are listed to the right.The most   likely fault is listed first, etc.   Start ing   Idling (low speed) (continued)   Idles with closed L-screw   Worn needle / needle tip   Difficult to start   Adjust the L-screw   Air filter blocked   Leaking diaphragm / coverplate   Control system sticking   Worn lever arm in the control   syste m   Choke does not work   Worn choke axle   Worn choke valve   Blocked fuel filter   Blocked or broken fuel line   Faulty diffuser jet   Piston ring s eized   Blocked