25Checking the safety chain brakeDo not work with the saw without first checking the chainbrake!Start the engine as described (make sure you have agood footing, and place the saw on the ground in such a waythat the blade is free of contact).Grasp the tubular handle firmly with one hand and holdthe rear handle with the other.With the engine running at moderate speed, press the handguard (7) in the direction of the arrow with the back of your handuntil the chain brake engages. The chain should stop immedi-ately.Immediately release the throttle and release the chain brake.IMPORTANT: If the chain does not stop immediately whenyou test the chain brake, do NOT use the saw! Take thesaw to a MAKITA service center for repair.C7EAdjusting the carburetor(only an authorized service center)CAUTION:Optimum perfornance can only be achieved if the car-buretor is adjusted correctly. For this work, which shouldbe carried out only by an expert, the engine must bewarmed up and the air filter must be clean.The carburetor has been adjusted by MAKITA on the basis ofatmosheric pressure conditions at sea level. Other atmospher-ic pressure conditions or the running-in process of a newengine may require readjustment of the carburetor.Set idle speedAdjust the idle speed using a screwdriver (8), blade width 0.16"(4 mm).If the chain turns when the engine is idling, unscrew thethrottle-valve stop screw (9) until the chain stops. If the engineruns unevenly, screw the screw (9) in.D98SERVICE