Yard-Man YM75 Operator's Manual

Contents

Yard-Man YM75 Operator's Manual Manual pdf 17 page image

17Idle Speed ScrewFigure 33SECTION 7: MAINTENANCE AND REPAIR INSTRUCTIONSCarburetor AdjustmentThe idle speed of the engine is adjustable through the airfilter/muffler cover. See Figure 33.NOTE: Careless adjustments can seriously damage yourunit. An authorized service dealer should makecarburetor adjustments.Check Fuel MixtureOld and/or improperly mixed fuel is usually the reason forimproper unit performance. Drain and refill the tank withfresh, properly mixed fuel prior to making anyadjustments. Refer to Oil and Fuel Information.Clean Air FilterThe condition of the air filter is important to the operationof the unit. A dirty air filter will restrict air flow and changethe air/fuel mixture. This is often mistaken for an out ofadjustment carburetor. Check the condition of the airfilter before adjusting the idle speed screw. Refer to AirFilter Maintenance.Adjust Idle SpeedWARNING: The cutting attachment mayspin during idle speed adjustments. Wearprotective clothing and observe all safetyinstructions to prevent serious personalinjury.If, after checking the fuel mixture and cleaning the airfilter, the engine still will not idle, adjust the idle speed asfollows.1. Start the engine and let it run at a high idle for aminute to warm up. See Starting/StoppingInstructions.2. Release the throttle trigger and let the engine idle. Ifthe engine stops, insert a small Phillips or flat bladescrewdriver into the hole in the air filter/muffler cover.See Figure 33. Turn the idle speed screw in,clockwise, 1/8 of a turn at a time (as needed) until theengine idles smoothly.NOTE: The cutting attachment should not rotate whenthe engine idles.3. If the cutting attachment rotates when the engine idles,turn the idle speed screw counterclockwise 1/8 of aturn at a time (as needed), to reduce idle speed.Checking the fuel mixture, cleaning the air filter, andadjusting the idle speed should solve most engineproblems.If this is not the case and the following are all true:• The engine will not idle• The engine hesitates or stalls on acceleration• There is a loss of engine powerHave the carburetor adjusted by an authorized servicedealer.WARNING: After turning the unit off, makesure the cutting attachment has stoppedbefore setting the unit down. This helpsprevent serious personal injury.