Many people are scared to touch their machine because it seems difficult. This is only true when you do not have the resources and tools available for when that time comes! This manual will easily pay for itself on the first oil change, spark plug change, or air filter change that you perform! The manual includes pictures and easy to follow directions on what tools are needed and how the repair is performed.
Just imagine how much you can save by doing simple repairs yourself. Many people buy this manual just to have it around for when the inevitable happens. Muffler Nuts. Ignition Module Fastener.
Electric Starting Motor Mounting Screws. A externally mounted oil cooler is located on the blower housing for the 25 hp engines. GENERAL The power plant for this unit is a air cooled four stroke two cylinder vertical shaft gasoline fueled normally aspirated engine. Fuel is provided by a pulse type fuel pump from the fuel tank to a non-adjustable carburetor.
Speed is controlled by a fly-weight type governor. A 15 Amp regulated charging system with externally mounted rectifier regulator provides operating current. Starting is by electric starting motor. No provision is provided for manual pull starting. Air flow is directed under the engine shroud and over the engine cooling fins. It is important that the intake screen remains open for proper air flow.
The engine shroud should never be altered or removed, as cooling capacity will be affected. Cylinder block and cylinder head cooling fins must remain clean and open to properly dissipate heat. Engines must never be overloaded or operated beyond the intended power range or rpm or overheating will occur.
The breather system consists of a reed valve, oil separator, and supply tube to intake manifold. A reed valve is located in each cylinder head and allows pressure out of the crankcase, but does not allowing air back in. A properly functioning reed valve maintains a partial vacuum in the crankcase.
This prevents oil from being forced out of the crankcase oil seals. The oil separator is located on one of the valve covers and separates oil from the air before it inters the air cleaner.
A gear driven Gerotor oil pump is located in the engine sump and provides oil under pressure to all major engine components. A external spin on type. The pumping action is created by the oscillation of positive and negative pressures within the crankcase. Two check valves prevent fuel from going backward through the pump. The carburetor has a electrically operated fuel shut off solenoid mounted externally on the fuel bowl that interrupts the fuel flow to the main jet when the operator turns of the ignition switch.
The carburetor contains no serviceable components. The outer, foam, element is removable and can be cleaned and reused.
Air enters the air filter from the opening in the cover and is filtered. Clean air is drawn into the carburetor and the engine for combustion. Throttle valve position and engine speed is controlled by the engine governor. The governor lever is being acted on by two forces, in opposite directions; in one direction the pull of the throttle control lever and cable, in the other direction the centrifugal force of the governor flyweights inside the engine.
The governor flyweights will always override the pull of the throttle control spring once the engine reaches maximum governed speed. The governor gear and flyweights are located inside the crankcase and driven by the camshaft gear. As engine speed is increased, the flyweights are pushed outward by centrifugal force.
As the flyweights move outward they push on the plunger, which contacts the governor arm. When operating the engine under varying loads with a fixed throttle control lever position, the governor has the effect of maintaining a constant engine speed as the load increases.
This is because as the engine speed decreases because of the load, the governor flyweights move in, and the governor linkage allows the throttle valve to open, speeding up the engine. This will occur until the engine reaches maximum load, at which time the throttle is wide open.
The high idle limiter screw determines the amount of travel the throttle control lever can move, and amount of tension the governor spring can exert on the governor lever. This determines the governed high idle speed. As soon as the original pulse drops back to zero magnet clearing the coil , the capacitor in the delay circuit begins to charge. When the charge on the delay capacitor exceeds the charge on the charge pump capacitor the comparator changes state, activating the pulse generator.
Energy is then transferred to the primary of the output transformer. As the capacitor discharges, the current initiates a fast rising flux field in the transformer core. A high voltage pulse is generated from this action into the secondary winding of the transformer. This pulse is delivered to the spark plug. Ionization of fuel-air mixture in the spark plug gap occurs, resulting in an ark between the plug electrodes.
This spark ignites the fuel-air mixture in the combustion chamber. As the trigger pulse is generated, all associated circuits are reset, their capacitors discharged. The longer it takes the delay circuit to surpass the charge pump capacitor voltage, the later the trigger pulse will occur, retarding the timing accordingly. The corresponding magnetic field induces energy into the input coil.
The resultant pulse is rectified and charges a capacitor. As the magnet assembly completes its pass, it activates the triggering device which causes a semiconductor switch SCS to turn on. With the device switch ON, the charging capacitor is directly connected across the primary coil of the output transformer.
The resultant pulse is fed to the input of the conditioning circuit. The conditioning circuit shapes this pulse, putting it in a usable form for the additional circuits. This pulse starts the charge pump, which charges a capacitor in a linear fashion that can be directly related to the engine speed. At the same time the pulse resets the delay circuit for length of the pulse width.
Cylinder Worn. Check Compression and Vacuum. Install spare plug to avoid fuel spitting from the hole. Make sure to hold plug cap. Are sparks produced between high tension lead and engine block when control unit is replaced? No fuel in the tank. Closed shutoff valve. Clogged fuel filter. Closed shutoff YES solenoid. Check for plugged fuel passage. Check for plugged air passage.
Check shutoff solenoid. Check carburetor setting. Gradually open throttle valve by hand. Does engine speed drop or does engine stall at a certain position?
Plugged oil ring groove. High oil level. Worn valve stems and valve guides. Oil leakage along Governor Shaft Oil seals leaking. Head gasket leaking. Drain plug leaking. Air cleaner clogged. Carbon deposit in exhaust port and muffler. Carburetor not properly adjusted.
Too much oil in crankcase. Is timing advance operating correctly? If OK, replace ignition module and retest. Initial Adjustment: 1. Park tractor and engage parking brake. Disconnect headlight wiring harness and remove hood. Loosen the throttle cable clamp A enough to allow the throttle cable to slide freely through the clamp. Move throttle control lever, on the operators control panel, to FAST idle position. Rotate fast idle control arm until fast idle screw head contacts fast idle stop.
Clamp throttle cable in this position. Make sure the throttle linkage is connected to the governor arm and the throttle lever on the carburetor.
Loosen the nut holding the governor arm to the governor shaft. Move the governor arm towards the carburetor as far as it will move and hold. Insert a pin or small punch into the hole on the governor shaft and rotate the shaft counterclockwise as far as it will turn, then tighten nut.
Remove the pin or punch. Replace air filter backing plate. Start engine and use fast idle screw to adjust fast idle to specification. Specification: All Engines. Perform sensitivity adjustment. Reason: To make sure that the choke plate is fully closed when the choke control is retracted and fully open when choke control is fully depressed. Test Procedure: A. Park tractor and set parking brake. Remove air cleaner. Look in carburetor to make sure that choke is closed.
Governor sensitivity is adjusted by repositioning the governor spring in the holes on the governor arm. If speed surging occurs with a change in engine load the governor is set to sensitive. Readjust fast idle to specification. Look in carburetor to make sure that choke is fully open. Adjustment Procedure: 1. Park machine on level surface. Turn key switch OFF. Loosen screw A securing choke cable and slide cable away from engine as far as it will go.
Tighten screw. If not, inspect linkage and choke plate for damage, replace parts as required. Engine will be HOT. Be careful not to burn hands. Move throttle control lever to FAST idle position. Specification: M If not, slightly bend choke linkage B slightly until choke is closed. DO NOT overbend. Re-check open position. Procedure All Engines : 1. Move throttle control lever to SLOW idle position. Recheck the slow idle speed using a Digital Pulse Tachometer at the spark plug wire.
Park machine on level surface and turn key switch OFF. Raise or remove optional engine hood. Move throttle control lever to FAST idle position — throttle and choke plates must be fully open to obtain an accurate reading. If not, the intake valve will be open and the leak test will be invalid.
Remove valve covers. Screw the adaptor into the spark plug hole but do not attach it to the tester at this time. Battery must be at a full state of charge to perform test. Charge battery first, if necessary. Crank engine until gauge needle settles out at its highest position. Let us know if you have any catalog for exchange. Switch to mobile version. Payment Conditions. Return and Refund Policy. Contact us.
Quick Send E-Mail. All repair manual spare parts catalog Diagnostic Software Diagnostic adapter interface. Have something to exchange? If you have a catalog, that we do not have in our list, we would gladly discuss the details of exchange or purchase.
0コメント