R-TEK/DURAFORCE (E) ENGINE SERVICE MANUAL Table of Contents – Page 1 of 1 PREFACE SAFETY SPECIFICATIONS SPECIAL TOOLS TROUBLESHOOTING MAINTENANCE CARBURETOR FUEL SYSTEM IGNITION SYSTEM REWIND STARTER ENGINE PIVOTING ZONE START BRAKE ELECTRIC START SYSTEM (120 VOLT) ELECTRIC START SYSTEM (12 VOLT)
PREFACE ABOUT THIS MANUAL This manual was written expressly for the E series engines. There are two engines in this series. One is piston ported (R tek) and the other is a reed valve (DuraForce). As these engines are of the same family, they will both be covered here. Where there are differences between the two versions, a heading will state which engine is being discussed. We have made every effort to make this information complete and correct.
TABLE OF CONTENTS TABLE OF CONTENTS SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Engine Specifications (All dimensions are for a new engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TABLE OF CONTENTS CARBURETOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TABLE OF CONTENTS REWIND STARTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Removal and Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 Reassembly .
TABLE OF CONTENTS ELECTRIC START SYSTEM (12 VOLT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 Starter Removal . .
SAFETY SAFETY INFORMATION General This safety symbol means WARNING or PERSONAL SAFETY INSTRUCTION - read the instruction because it has to do with your safety. Failure to comply with the instruction may result in personal injury or even death. This manual is intended as a service and repair manual only. The safety instructions provided herein are for troubleshooting, service, and repair of the engine only.
SPECIFICATIONS Specifications Engine Specifications (All dimensions are for a new engine) Item DuraForce R tek Type Reed valve 2-cycle Piston ported 2-cycle 2.5000" + .0005 (63.5mm + .0127) Bore 1.75" (44.45mm) Stroke Wrist pin diameter .5000" + .0000 - .0002 (12.70mm + .000 - .005) Crankpin diameter .7427" + .0003 - .0002 (18.85mm + .008 - .005) End play (crankshaft) . Side play (crankshaft) near lower main 0 - .017" (0 - .431mm) 1998 Snow 0 - .0215" (0 - .533mm) 1999 and later Snow 0 - .
SPECIFICATIONS Item DuraForce R tek Choke Manual, butterfly type Fuel filter In-tank and in-carburetor Cast iron, semi-keystone top ring. Second ring is rectangular. Anti-rotation pin in piston. Piston rings Piston Permanent mold, high silicon aluminum Engine Fastener Torque Requirements Item DuraForce R tek Bolt, Head 140 - 200 in. lbs. (16 - 22 Nm) 140 - 200 in. lbs. (16 - 22 Nm) Jet, Main 4 - 6 in. lbs. (.44 - .66 Nm) 4 - 6 in. lbs. (.44 - .66 Nm) Jet, Pilot* 10 - 12 in. lbs. (1.1 - 1.
SPECIFICATIONS Item DuraForce R tek Nut, Shroud 100 - 130 in. lbs. (10 - 14 Nm) 140 - 170 in. lbs. (16 - 19 Nm) Screw, Starter Bracket to Recoil NA 30 - 35 in. lbs. (3.4 - 3.8 Nm) Screw, Gov Pivot Block to Cyl. NA 30 - 35 in. lbs. (3.4 - 3.8 Nm) Screw, Elect Start to Crankcase 140 - 200 in. lbs. (16 - 22 Nm) 75 - 100 in. lbs. (8.2 - 11 Nm) Standard Torques Size US (Metric) #10 - 24 20 - 30 in. lbs. (5.1 - 6.21 Nm) 1/4 - 20 55 - 90 in. lbs. (6.2 - 10.0 Nm) 5/16 - 18 140 - 200 in. lbs.
SPECIAL TOOLS SPECIAL TOOL REQUIREMENTS Listing Description Order From Part Number Comments/Use Air Gap Gauge Toro 604659 Sets .010” (.
TROUBLESHOOTING TROUBLESHOOTING Engine Will Not Start When “Cold” Possible Causes Remedies Fuel tank is empty Fill with clean, fresh, properly-mixed, unleaded fuel Bad fuel Drain tank and float bowl. Fill the tank with clean, fresh, unleaded, properly-mixed fuel.
TROUBLESHOOTING Engine Will Not Produce Spark Possible Causes Remedies Spark plug wire disconnected Reconnect spark plug wire Spark plug fouled or damaged Replace spark plug Spark plug wire damaged Replace CD pack Coil kill wire grounded Locate and eliminate the unwanted ground Ignition coil failed Replace CD pack Flywheel magnets weak Replace flywheel Engine Flooded With Fuel Possible Causes Remedies Overuse of choke position Take throttle off choke Throttle cable misadjusted Adjust thro
TROUBLESHOOTING Engine Lacks Power Possible Causes Remedies Dull blade Sharpen or replace blade, mower only Housing choked with grass and debris Clean housing thoroughly, mower only Plugged exhaust system Clean exhaust ports Muffler plugged Clean or replace muffler Flywheel key sheared Replace flywheel key Carburetor dirty Clean carburetor Intake air leak Repair or replace failed components(s) Low compression See “Engine Has Low Compression” table Engine Surges Possible Causes Remedies F
TROUBLESHOOTING Engine Overheats Possible Causes Remedies Cylinder head cooling fins clogged Clean fins thoroughly Restricted carburetor jets Clean carburetor and jet Improper gas to oil mix ratio Ensure mixture is correct Cooling air intake plugged Remove foreign material and clean Engine Vibrates Excessively Possible Causes Remedies Blade out of balance Balance blade or replace if damaged Bent blade Replace blade Loose engine mounting screws Tighten engine mounting screws (engine to plate
TROUBLESHOOTING Engine Pre-Ignites Possible Causes Remedies Wrong spark plug - too hot Install the correct type of spark plug Low quality fuel (old or stale) Replace with fresh, unleaded regular fuel Carbon buildup in engine Decarbon engine and muffler Excessive alcohol in fuel Replace with fresh unleaded fuel having no more than 10% ethanol Sheared flywheel key Inspect and repair Engine Smokes Excessively (Smoke is light colored, engine runs well) Possible Causes Remedies Slight oil accumulat
TROUBLESHOOTING Engine Stalls Possible Causes Remedies Engine out of fuel Refill with fresh fuel of the correct mixture Engine overloaded Unload engine and restart Fuel filter plugged Clean fuel filter/tank Spark plug fouled See “Spark Plug Fouled” table Fuel cap vent plugged Replace fuel cap Ignition inadvertently grounded Inspect and repair to remove unwanted ground Carburetor vent plugged Clear vent of obstruction Engine overheated Clear debris from fins or cause of overheating Improper
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MAINTENANCE Recommended Maintenance Schedule Frequency Item Comments 5 Hours Fasteners Check blade and engine mounting fasteners frequently. Keep all nuts, bolts, and screws tight to ensure safe operation. 25 Hours Housing (Mower only.) Remove the buildup of grass clippings and dirt. (Self-propelled mower only.) Clean grass clippings and debris under drive belt mechanism cover and drive belt. 50 Hours Spark Plug Clean, inspect, and regap; replace if necessary. Air Filter (Mower only.
MAINTENANCE Air Filter (Mower Only) Note: Be sure filter is properly seated in air box and is not puckered (allowing direct passage of air and dirt to carburetor). Once every season, or every 50 hours, clean the air filter housing and element. Do so more frequently under dusty conditions. Note: Do not operate the engine without the air filter in place. Doing so may damage the engine or cause excessive engine wear. 1. To remove air filter (A), snap cover latch open, swing to side, and unhook.
MAINTENANCE Cleaning the Exhaust System (Lawn Mower) Warning: Disconnect the spark plug wire to prevent accidentally starting the engine. A 1. (Mower) Using a 1/2" drive with a 15/16" socket, remove the blade nut that secures both the mulch fan and blade to the engine. Use heavy-duty gloves to hold the blade while removing the nut. (See Figure 6.) Note: Removing the blade is merely for convenience while working. B Figure 8 1657-001 3.
MAINTENANCE Cleaning the Exhaust System (Snowthrower) Reassembling Exhaust System (Mower Only) 1. Remove the muffler (see Figure 10.) Clean as needed. 1. Install the exhaust pipe into the engine base (see Figure 12). Figure 12 Figure 10 0893-012 16547-006 2. The cover on the exhaust portion of the engine base uses a high temperature silicone to seal the joint. Apply a coat of Loctite 598 or equivalent to the sealing surfaces before assembly. Torque the four screws per specifications. 2.
CARBURETOR Identification The E series engines use two versions of the primer start carburetor. One with an air filter box on the mower engines (DuraForce) and one without an air filter box on the snowthrower engines (R tek). Differences include a plug in the snowthrower carburetor vent passage and some minor differences in the throttle shafts, jetting and throttle valve bleed hole. Both carburetors have two circuits and use both a choke and primer for starting. (See Figure 13.) Figure 14 3297-012 A.
CARBURETOR Troubleshooting Engine Starts Hard Possible Causes Remedies Primer malfunction Repair or replace as necessary No fuel in carburetor Add the proper fuel-oil mix Carburetor bolts loose Tighten bolts to 20 - 30 in.lbs. (2.2 - 6.
CARBURETOR Fuel Leaks From Carburetor (Leaking starts after running, stops after shutdown) Note: This condition which does NOT drain the fuel tank is called “spit-back”.
CARBURETOR 5. Disconnect the primer tube from the carburetor fitting. (See Figure 19.) 4. Disconnect the primer tube from the carburetor fitting (see Figure 19). 6. Pull the carburetor assembly down and away from the engine such that the air vane governor clears the hole in the shroud mounting base. 5. Disconnect the governor spring from the adjustment arm, and remove the choke cable. (See Figure 19.) 7. Remove the throttle cable screw and nut from the throttle cable mounting bracket.
CARBURETOR 2. Hold the governor collar on the carburetor and lift the air vane/throttle shaft out of the carburetor. For DuraForce engines only - Lift the collar and spring up, detaching the spring from the speed control lever. (See Figure 21.) 4. The pilot jet is located under the decal on the side of the carburetor. Remove the decal and the pilot jet. Note: The threads have Loctite on them. (See Figure 23.) Figure 23 Figure 21 0893-005 5. Remove the fuel filter from the fuel nozzle (see Figure 24).
CARBURETOR 6. Remove the float hinge pin, the inlet valve needle assembly (with its clip), and the float (see Figure 25). Discard the needle and clip. 9. Remove the high speed jet (A) from the nozzle (B). It is best to clean the nozzle in place. If the nozzle is not sealed into the carburetor body, the air/fuel mixture will be affected (see Figure 28). Note: There are two white nylon plugs in each carburetor. Do not attempt to remove them or the carburetor will be damaged. Figure 25 0893-18 A 7.
CARBURETOR Assembly 4. Apply one drop of Loctite 242 or equivalent to the seat threads, and install a new brass inlet fuel valve seat (see Figure 31). 1. Install the high speed jet into the fuel nozzle. 2. If the nozzle has been removed, turn the carburetor over. Apply one drop of Loctite 242 blue or equivalent to the nozzle threads, and install the nozzle assembly into the carburetor body (see Figure 29). Figure 31 0893-041 5. Install a new inlet valve needle and clip on the float. Figure 29 6.
CARBURETOR 8. Pressure check carburetor. Attach pump with pressure gauge to fuel inlet fitting on carburetor (see Figure 33). With carburetor upside down (float up), raise float and lower to its normal position. Pump pressure to 5 psi. It should hold this pressure indefinitely. For practical purposes, test for 10 or 15 seconds. If it does not hold, wet the needle and seat, and repeat the test. 10. Install a new fuel bowl gasket and the fuel bowl with the four bowl retaining screws (see Figure 35).
CARBURETOR 13. Install the air vane and throttle shaft into the carburetor body by very carefully pushing the shaft through the collar into the carburetor body. (See Figure 37.) A 14. Push the throttle plate into the throttle shaft. (The plate only inserts one way.) If the throttle plate does not fit snugly, replace the throttle shaft. The governor spring can now be attached to the throttle shaft. Note: Be sure air vane operates smoothly and does not stick or bind. B Installation Figure 38 1.
CARBURETOR 2. Use a tachometer to check engine speed; 2900 ± 300 RPM for DuraForce engines on mowers. For R tek (piston ported) engines refer to the specification pages. Should the governor link (A) be bent or replaced, adjustment will be necessary. (See Figure 41.) Figure 39 0720-07 Piston Ported Engine (R tek Engines Only) A The piston ported engine does not use the “click" type adjustment.
CARBURETOR Servicing the Air Filter (DuraForce Engines Only) 1. To remove the air filter, unsnap the wire holder on the right side of the cover the cover. Rotate the cover open. The air filter element can now be removed. If you wish to remove the cover, rotate it full open and unhook it from the hinge. (See Figure 43.) Figure 43 0893-017 2. Clean and re-oil the air filter element according to the procedure in Maintenance section.
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FUEL SYSTEM Operation Fuel Cap Service The E engine uses a plastic fuel tank with a nonreplaceable 75 micron in-tank filter screen. The filter is welded in the bottom of the tank over a sediment reservoir. The tank is mounted above the level of the carburetor and uses gravity to supply fuel through a .25" I.D. (6.35 mm) rubber hose to the carburetor. The fuel hose is friction-fitted to the tank outlet at one end and to the carburetor at the other end. 1.
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IGNITION SYSTEM Troubleshooting Problem Possible Cause Suggested Remedy Misfiring, no firing, engine surges, engine dies (Note: these symptoms may also be caused by fuel system problems) Spark plug or lead wire loose Tighten plug Spark plug in poor condition Replace plug CD Pack air gap wrong Adjust CD Pack high tension lead loose Secure with GE silicon sealant CD Pack leads loose, dirty, or grounding Clean and tighten leads/replace CD Pack defective Replace CD Pack Flywheel key damaged or s
IGNITION SYSTEM Spark Plug Service 1. Check spark plug with the chart in this subsection and replace following the specifications given on this page. CAUTION: Do not clean plug with a sand blaster. 2. Clean with a wire brush removing the carbon buildup. Check conditions of the plug for cracking or damage. Replace as necessary.
IGNITION SYSTEM CD Pack Air Gap Adjustment At slower speeds, the flywheel magnet induces a smaller charge in the trigger coil. This action triggers the silicon controlled rectifier (SCR) enabling easier starting in a “retarded firing position” about 5 degrees before top dead center (BTDC). (See Figure 50.) 1. Rotate the flywheel until the magnets are directly adjacent to the CD Pack as shown. (See Figure 52.) .010” (.25 mm) Figure 50 A. Pole Shoe B. Flywheel Rotation C. Crankshaft at 5° BTDC D. E. F.
IGNITION SYSTEM Flywheel Operation 3. Remove the flywheel by pulling up on the edge of flywheel while striking the flywheel nut with a soft hammer. (See Figure 55.) The flywheel is connected directly to the crankshaft (secured by a flywheel key and nut) and turns at the same speed as the crankshaft. Two permanent magnets, imbedded in the flywheel, rotate past the coil in the CD Pack to begin the generation of electricity.
IGNITION SYSTEM 6. Inspect the flywheel for cracks or damage and the strength of the magnets using a iron object. Replace as necessary. (See Figure 57.) 4. Torque flywheel nut to specifications (see Figure 59.) Figure 59 Figure 57 0893-013 Flywheel Installation 1. Make sure flywheel taper, crankshaft taper, and keyway is absolutely clean and dry. 2. Make sure key is installed correctly (see Figure 58.) 3. Locate keyway cutout in flywheel over key and shaft.
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REWIND STARTER Operation 4. This recoil starter is a pressed together assembly. Due to the low cost of the assembly, we do not stock individual parts. Should the recoil fail due to something other than a starter rope, we recommend replacing the assembly. The replacement recoil will be connected to the shroud with nuts and bolts.
REWIND STARTER 2. Tie a single knot in the end of the rope; then singe the end with a lighter to prevent the knotted end of the rope from fraying (see Figure 62). Tie a simple knot in the rope to prevent too much from retracting until the starter handle is installed. Figure 62 lbv0043d.bmp 3. Reassemble the starter and shroud with the four screws and nuts. Remember the orientation of the rope outlet. 4.
ENGINE General Information In this section, we will cover both versions of the E series engine. The DuraForce is a reed valve engine, and the R tek is piston ported. The design difference affects the path which the incoming fuel/air charge takes to get to the firing chamber. Two-cycle engines have special advantages which make their use more practical in certain applications.
ENGINE Piston Ported Engine In a piston ported engine, there are no reed valves. The fuel/air mixture enters the crankcase through a third port that is opened and closed by the piston. (See Figure 66.) All other functions are the same as a reed valve engine. When the piston opens the exhaust port, high-pressure exhaust gases exit the exhaust port. (See Figure 68.
ENGINE Service Tips 2. Remove the entire crankshaft assembly, and discard the oil seals. 1. Cylinder/Crankcase Halves The two halves are a matched pair and cannot be exchanged between engines. Follow all cleaning and assembly procedures in this subsection. Be sure to use Loctite 515 on the mating surfaces. Torque the six screws that secure the two halves. See specifications. 2. Oil Seal Visually inspect for leaky or damaged oil seals (two locations). See the Seal Service section for the procedure.
ENGINE 4. Remove the piston and rod assembly. Separate the assembly if necessary, using a snap ring pliers on the retaining ring (16). Use wrist pin knock out tool (P/N 602884) to punch out wrist pin (17). (See Figure 72.) 3. Check all parts for wear or damage and replace if questionable. 4. Clean crankcase surfaces with Gel Seal and Gasket Remover. (See Figure 74.) 17 16 Figure 72 Figure 74 0893-24b 5. Use a feeler gauge to check that the ring end gap is to specifications. 5.
ENGINE A. Vertical scratches that appear all the way around the piston sometimes is combined with discoloration (see Figure 76). Scratches all the way around the piston indicate high hours or dirt ingestion. If the scratches are in limited areas, look more closely to see if they are in line with the ports. On a NEW engine, if the ports are not properly deburred, piston damage can result. This can appear ONLY on engines with very few hours on them. The damage is immediate.
ENGINE 3. When replacing reeds, install smooth edge down centered over openings in crankcase (see Figure 78), and use Loctite 271 on threads of screws. Torque per specifications. 2. Several piston and ring combinations have been used. Pistons have been plated and unplated. Pistons have used two keystone rings and others used one semi-keystone and one standard ring. The pistons made for one type of ring will not accept the other type. However, any piston and ring assembly can be used in any cylinder.
ENGINE 7. Apply Loctite 515 gasket maker very thinly to the crankcase cover sealing surface (A), being careful not to get sealant in bearings. (See Figure 81.) 9. Tighten the screws to specifications, tightening only 20 in. lbs. (2.26 Nm) increments at a time while tightening modified (X) pattern. (See Figure 83.) 6 A 1 2 3 Figure 81 4 5 0720-018 Figure 83 8. Carefully align the two crankcase halves using the alignment pin (A) and its matching hole. Press the two halves together. (See Figure 82.
ENGINE Crankshaft Seal Replacement Separate the crankcase from the cyclinder to replace the seals. Slide the seals off the crankshaft and clean the case mating surfaces as previously indicated. Clean the block where the seal goes and the outside of the seal with alcohol to ensure they are oil free. If oil is in the bore or on the seal O.D. the lubrication may cause the seal to move when hot.
PIVOTING ZONE START BRAKE Operation PIVOTING ZONE START BRAKE (DuraForce Engines Only) Introduction The pivoting style zone brake system has two main functions. The first function of the system is to stop the production of spark and the second is to stop the engine and the blade. In 1982, the federal government mandated that all consumer walk behind mowers with a cut of 25" (63.5 cm) or less be equipped with safety devices.
PIVOTING ZONE START BRAKE There are two versions of this brake. The function is the same, but they contact different parts of the flywheel. Figure 88 is a diagram of the system used on recoil start engines. The brake pad engages the bottom of the flywheel. Figure 89 is a photo of a slightly different system used on electric start engines. On electric start engines, the brake pad must contact the side of the flywheel to clear the teeth of the flywheel ring gear.
PIVOTING ZONE START BRAKE Assembly 6. Operate the blade control bail to verify that the brake mechanism stops within three (3) seconds. There is no adjustment needed after this assembly process is completed. (See Figure 91). 1. If the brake mounting plate was not removed from the engine, simply reconnect the grounding lead to the push-on terminal directly above the ground strap stop (4) and continue with the reassembly process.
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ELECTRIC START SYSTEM (120 VOLT) Troubleshooting Starter Motor Fails to Turn Possible Cause Correction Power not reaching product Plug another appliance into extension cord to ensure cord is OK. Starter switch malfunction Check switch using a volt/ohmmeter set for resistance. Ensure that there is continuity when the switch is depressed. Engine has seized Verify that the engine turns over freely.
ELECTRIC START SYSTEM (120 VOLT) Starter Disassembly Starter Assembly 1. Remove the pinion retaining clip by applying constant pressure towards the end of the shaft on one end of the clip and working around the rest of the clip. Always replace clip with a new one. Assemble by reversing the disassembly process. 2. Slide the stop washer, pinion spring, and pinion off the shaft. Install by reversing the removal procedure. Starter Installation 3.
ELECTRIC START SYSTEM (12 VOLT) Troubleshooting Starter Motor Fail to Turn Possible Cause Correction Starter motor has failed Check by disconnecting the spark plug wire and starter wiring connector. Apply 12 volts directly to the starter motor. (Note: Due to the connector arrangement, it is possible that the starter motor will turn backwards during this test. This does not harm the motor.) Battery has low charge or is disconnected Check battery for full charge and ensure it is connected.
ELECTRIC START SYSTEM (12 VOLT) 4. Remove the bolt that secures the lower bracket to the chassis. Remove the starter. While removing, be careful not to move the starter side to side as you may bend the pinion shaft. (See Figure 97.) 2. Remove the two screws and drag-spring stud (A) that secure the gear cover plate to the motor housing. (See Figure 99.) Remove the cover plate. Note that the plate has “OUT” stamped on the top. During installation “OUT” must face the pinion/clutch assembly.
ELECTRIC START SYSTEM (12 VOLT) Starter Assembly 5. Reassemble pinion/clutch assembly. Apply a small amount of Lawn-Boy “AX” grease to the pin. Slide the assembly on to the pin with the drag spring (A) over the stud. (See Figure 102.) 1. Apply a light coat of Lawn-Boy “AX” grease to the pinion gear, thrust washer, and driven gear prior to installation. A 2. Place the pinion gear on small driveshaft in motor housing with either side facing up. (See Figure 101.) 3.
ELECTRIC START SYSTEM (12 VOLT) Alternator Introduction charge rate, it is important to use the 120 volt charger to fully charge the battery before initial use and at the start of each season. Frequent starts or hard starting may require using the 120 volt charger to recharge the battery. (See Figure 103.) Electric start DuraForce engines are equipped with an alternator to keep the battery “topped off”. The charge rate of this alternator is 500 milliamps. Due to the low Figure 103 12v.
ELECTRIC START SYSTEM (12 VOLT) Alternator Output Testing Alternator Resistance Check 1. To check output of the alternator accurately, it is necessary to run the engine at operating speed, 2900 ± 300 RPM. Readjust the governor if necessary. Refer to page 26 (Presetting the Governor (DuraForce Engines Only). 1. Disconnect the electronic cup assembly from the wiring harness. Connect one ohmmeter (RX-1 scale) lead to the green wire of the wiring harness and the other to the engine block. (See Figure 105.
ELECTRIC START SYSTEM (12 VOLT) 3. Measure resistance. Reverse leads and measure resistance again. The specification is to have different resistance between the two measurements — high one way and low the opposite way. If specification is not met, replace the cup assembly. (See Figure 106.
