National Mower 99500500-8400 Owner's/operator's Manual

National Mower 99500500-8400 Owner's/operator's Manual Manual pdf 12 page image

GB - 12MOWING1. Stop tractor by releasing the tractionpedal (8, Figure 1), then slowly lower themower units.2. Engage reel control switch (10, Figure 1)to the "On" position.3. Depress traction pedal to the desiredspeed (see Traction Pedal on page 9and Speed Control on page 9). Reelspeed is constant and ground speed isvariable with the traction pedal. Do nottry to regulate ground speed with enginethrottle (see Throttle Lever on page 9).VERTICAL MOWING UNIT1. Be aware that the blades can extendbelow the roller. Use care when loweringcutting units down onto a hard surface toavoid bending the blades.2. Setting the depth of cut: Always startwith shallow, less aggressive cuts. Setthe blades to zero (blade tips even withbottom of roller). Gradually increasedepth of cut until suitable results areobtained (see HEIGHT OF CUTADJUSTMENT on page 18).3. Keep in mind that vertical mowing issimilar to cutting grass; you can be tooaggressive. When vertical mowing grassthat has never been vertical mowed,avoid going too deep to start with.Gradually increase the depth of cut toobtain desired results.HILLSIDE OPERATIONThe 8400 has been designed for goodtraction and stability under normal mowingconditions. However, caution must still beused during slope operation, especially whenthe grass is wet.Wet grass limits traction and steering control.In order to minimize the possibility of tipping,the least dangerous method of operating onhills and terraces is to travel horizontally tothe hill. It is also advisable to avoid anyunnecessary turns while operating on hills.Use extreme caution and travel at reducedspeeds.1. When operating on hillsides or slopes,maintain full engine speed, but let up onthe traction pedal as powerrequirements increase. This willmaintain the performance necessary.2. It is best to mow along the side of thehill, starting at the bottom and workingupwards. This allows the machine tonegotiate the slope without mowing in adownhill direction.3. It is essential for the correct tire pressureto be established for maximum tractionand hillside holding.PUSHING OR TOWINGINSTRUCTIONSThe 8400 has a free-wheeling valve, or “towvalve,” which will permit moving the machineat slow speeds without starting the engine.Do not exceed 2 mph (3 km/h) while pushingor towing (see Free-Wheeling Valve onpage 9).AFTER OPERATION1. Clean the entire mower after use.Remove loose grass clippings andcaked grass to prevent clogging thevented lubrication points and corrodingparts.2. The engine is air cooled. Do not permitdirt or grass clippings to accumulate onthe air intake screen, cylinder heads, oron hydraulic pump cooling fan to preventserious heat damage to the engine orhydraulic pump.3. If fan blades become damaged, replacethe fan.CAUTION: Dropping cutting unitsabruptly could damage them or theH-frame of the wing mowers.CAUTION: Dropping the verticalcutting units abruptly could damagethe blades and/or the H-frame of thewing mowers.