Stihl HT 103 Product Instruction Manual - Page 32

English Operating Instructions During Break-In Period A factory-new machine should not be run at high revs (full throttle off load) for the first three tank fillings. This avoids unnecessary high loads during the break-in period. As all moving parts have to bed in during the break-in period, the frictional resistances in the engine are greater during this period. The engine develops its maximum power after about 5 to 15 tank fillings. During Operation NOTICE Do not make the mixture leaner to achieve an apparent increase in power - this could damage the engine - see "Adjusting the Carburetor". Check chain tension frequently A new chain has to be retensioned more often than one that has been in use for some time. Chain cold Tension is correct when the chain fits snugly against the underside of the bar and can still be pulled along the bar by hand. Retension if necessary - see "Tensioning the Saw Chain". Chain at operating temperature The chain stretches and begins to sag. The drive links must not come out of the bar groove - the chain may otherwise jump off the bar. Retension the chain - see "Tensioning the Saw Chain". After long period of full-throttle operation Allow engine to run for a short while at idle speed so that engine heat can be dissipated by the flow of cooling air. This protects engine-mounted components (ignition, carburetor) from thermal overload. After Finishing Work N Slacken off the chain if you have retensioned it at operating temperature during cutting work. NOTICE Always slacken off the chain after finishing work. The chain contracts as it cools down. If it is not slackened off, it can damage the gear shaft and bearings. Storing your saw for a short period Wait for the engine to cool down. Drain the fuel tank. Store the machine in a dry location. Check the tightness of all accessible screws and nuts (not adjusting screws) at regular intervals and retighten if necessary. Storing for a long period See chapter on "Storing the Machine" Taking Care of the Guide Bar 2 246BA028 KN 1 3 N Turn the bar over every time you sharpen the chain and every time you replace the chain - this helps avoid one-sided wear, especially at the nose and underside of the bar. N Regularly clean the oil inlet hole (1), the oilway (2) and the bar groove (3). N Measure the groove depth - with the scale on the filing gauge (special accessory) - in the area used most for cutting. Chain type Chain pitch Picco 1/4" P Minimum groove depth 4.0 mm (0.16 in) If groove depth is less than specified: N Replace the guide bar. 30 HT 102, HT 103, HT 132, HT 133