Instruction Manual
Page 5
...in this service manual. Check disassembled parts for wear or damage before carrying out repairs or mounting the machine to overheating. 4 MS 231, MS 231 C, MS 251, MS 251 C Fuel system - Do not re-use fuel hoses after working on the fuel system and the engine. fuel hoses can ... and warnings in position - Gasoline is otherwise a risk of injury from the fanwheel and a risk of STIHL press fluid, b 14. Preparations for servicing Remove the chain sprocket cover, saw chain and guide bar before re-installing - Always use sharp-edged pliers, screwdrivers, etc. Do not cut open...
...in this service manual. Check disassembled parts for wear or damage before carrying out repairs or mounting the machine to overheating. 4 MS 231, MS 231 C, MS 251, MS 251 C Fuel system - Do not re-use fuel hoses after working on the fuel system and the engine. fuel hoses can ... and warnings in position - Gasoline is otherwise a risk of injury from the fanwheel and a risk of STIHL press fluid, b 14. Preparations for servicing Remove the chain sprocket cover, saw chain and guide bar before re-installing - Always use sharp-edged pliers, screwdrivers, etc. Do not cut open...
Instruction Manual
Page 9
... under full load Cause Clutch shoes badly worn Clutch drum badly worn Remedy Install new clutch Install new clutch drum Saw chain rotates at idle speed Engine idle speed too high Clutch springs stretched Clutch springs broken Readjust idle speed screw LA Replace the clutch springs or ... Clutch shoe retainer broken Clutch shoes and carrier worn Replace all clutch springs Fit new needle cage Install new retainer or clutch Install new clutch 8 MS 231, MS 231 C, MS 251, MS 251 C
... under full load Cause Clutch shoes badly worn Clutch drum badly worn Remedy Install new clutch Install new clutch drum Saw chain rotates at idle speed Engine idle speed too high Clutch springs stretched Clutch springs broken Readjust idle speed screw LA Replace the clutch springs or ... Clutch shoe retainer broken Clutch shoes and carrier worn Replace all clutch springs Fit new needle cage Install new retainer or clutch Install new clutch 8 MS 231, MS 231 C, MS 251, MS 251 C
Instruction Manual
Page 10
... drum badly worn Brake band blocked Install new clutch Install new clutch drum Check freedom of movement and operation of brake band Saw chain rotates at idle speed Engine idle speed too high Clutch springs stretched Clutch springs broken Readjust idle speed screw LA Replace the ...clutch springs or install new clutch Replace the clutch springs Saw chain does not stop immediately when brake is activated Brake spring stretched or broken Fit new brake spring Brake band stretched or worn Clutch drum worn Fit new brake band Install new clutch drum MS 231, MS 231 C, MS 251, MS 251 C 9
... drum badly worn Brake band blocked Install new clutch Install new clutch drum Check freedom of movement and operation of brake band Saw chain rotates at idle speed Engine idle speed too high Clutch springs stretched Clutch springs broken Readjust idle speed screw LA Replace the ...clutch springs or install new clutch Replace the clutch springs Saw chain does not stop immediately when brake is activated Brake spring stretched or broken Fit new brake spring Brake band stretched or worn Clutch drum worn Fit new brake band Install new clutch drum MS 231, MS 231 C, MS 251, MS 251 C 9
Instruction Manual
Page 17
...closed Tank vent faulty Clean the carburetor Reset low speed screw (L) correctly Reset idle speed screw (LA) correctly Replace tank vent Saw chain rotates at idle speed Leak on fuel hose from tank to carburetor Seal connections or install new fuel hose Engine idle speed too...) Clutch springs stretched or fatigued Replace the clutch springs or install new clutch Clutch spring hooks broken Replace the clutch springs 16 MS 231, MS 231 C, MS 251, MS 251 C Condition Cause Remedy Engine will not idle, idle speed too Throttle shutter opened too wide by Reset idle speed screw (LA...
...closed Tank vent faulty Clean the carburetor Reset low speed screw (L) correctly Reset idle speed screw (LA) correctly Replace tank vent Saw chain rotates at idle speed Leak on fuel hose from tank to carburetor Seal connections or install new fuel hose Engine idle speed too...) Clutch springs stretched or fatigued Replace the clutch springs or install new clutch Clutch spring hooks broken Replace the clutch springs 16 MS 231, MS 231 C, MS 251, MS 251 C Condition Cause Remedy Engine will not idle, idle speed too Throttle shutter opened too wide by Reset idle speed screw (LA...
Instruction Manual
Page 21
...or stretched brake spring has the same negative effect. 5.2 Brake Band - Troubleshooting, b 3.2 - the chain must come areas on inside diameter and/or parts of the machine. 20 MS 231, MS 231 C, MS 251, MS 251 C the chain must not rotate. : Pry the brake band (2) out of its remaining thickness is one side and... from the underside of outside diameter - Its efficiency is measured in order if deceleration of the lockout lever on the chain saw chain coming to one of wear (large With the coasting brake disengaged, open the throttle wide for a brief 1 TOP period (max. ...
...or stretched brake spring has the same negative effect. 5.2 Brake Band - Troubleshooting, b 3.2 - the chain must come areas on inside diameter and/or parts of the machine. 20 MS 231, MS 231 C, MS 251, MS 251 C the chain must not rotate. : Pry the brake band (2) out of its remaining thickness is one side and... from the underside of outside diameter - Its efficiency is measured in order if deceleration of the lockout lever on the chain saw chain coming to one of wear (large With the coasting brake disengaged, open the throttle wide for a brief 1 TOP period (max. ...
Instruction Manual
Page 97
... full turn . Adjusting engine idle speed - Turn the idle speed screw (LA) clockwise until the engine runs and accelerates smoothly. Saw chain runs while engine is not satisfactory when operating at high altitude A minor correction may be removed for operation at high altitude. - Turn... lubrication and overheating. 96 MS 231, MS 231 C, MS 251, MS 251 C Troubleshooting, b 3.6 - Warm up the engine. - If the setting is made too lean there is usually necessary to the low speed screw (L). Turn the idle speed screw (LA) counterclockwise until the chain stops running behavior. Turn...
... full turn . Adjusting engine idle speed - Turn the idle speed screw (LA) clockwise until the engine runs and accelerates smoothly. Saw chain runs while engine is not satisfactory when operating at high altitude A minor correction may be removed for operation at high altitude. - Turn... lubrication and overheating. 96 MS 231, MS 231 C, MS 251, MS 251 C Troubleshooting, b 3.6 - Warm up the engine. - If the setting is made too lean there is usually necessary to the low speed screw (L). Turn the idle speed screw (LA) counterclockwise until the chain stops running behavior. Turn...