Generac-power-systems MC Bedienungsanleitung

MC ALTERNATORDIAGNOSTIC REPAIR MANUALISSUED JANUARY 1979P.0, BOX 8, WAUKESHA. WISCONSIN 53186 PRINTED IN U.S.A.51834

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RED CONNECTOR PLUG0RED RECEPTACLEoKslCelCjlLjlCa11 '—T1120V.CUSTOMERSCONNECTIONSFACTORY WIRING CONNECTIONS 120 VOLTS ONLY22144-CD □ d]j----- -L

SECTION 1.3SPECIAL TOOLSELEHTRICAL TEST PLUGThe Electrical Test Plug facilitates the testing of electrical components in circuits that pass through t

LOAD BANKThe Load Bank is used to apply an electrical load to alternators.. The unit is equipped with a Voltmeter, Ammmeter and Frequency Meter, as

PART IITROUBLE DIAGNOSISSection 2.1 2.1.1Section 2.2 Section 2,3- DIAGNOSTIC FLOW CHARTS- Introduction Engine won’t Crank Engine Cranks, won’t Start E

SECTION 2.1DIAGNOSTIC FLOW CHARTS2.1.1-INTROUUCTIONThe DIAGNOSTIC FLOW CHARTS that follow are intended for use with the DIAGNOSTIC TESTS in Section 2.

ENGINE CRANKS, WON’T STARTTEST 8PageCheckSpark2.2-^’IfTEST 9________ _______PageTEST 10Low Oil SwitchOIL LEVEL LOW |IF SPARK CHECKS GOOD GO TO TEST 15

TEST 19PageFuelFilter2.2-9IGOOD;TEST 22 PageCheckInstallation_2.2-11TEST 20PageFuelLock-Off ; SolenoidL2-10 ____1bad!BADTREPLACEREPLACETEST 21PageFuel

IF COMPRESSION IS GOOD, GO TO TEST 29rTEST 27PageRings 2.. 1 i ’-.2-14 good:BADVREPIACE17TESTTEST 28 Page Cylinder 2.2-14\ I I ‘ *BADREPAIR77TESTT

This Repair Manual is provided to aid the technician in the analysis and repair of malfunctions that might occur in the MC alternator or its engine. K

AREPAIRREPLACEREPAIRSWITCH SET TO STOP - ENGINE KEEPS RUNNINGTEST 3 jPagejReplace Switch2.1-5

A-C VOLTAGE LOWTEST 33PageCheckFrequency2.2-17 ____iB/1IdTEST 32PageGovernor2.2-17Bi<L:goodA-C POWER LOW2*1-6

A-C VOLTAGE HIGHTEST 36PageCheck Output ; Voltage>.2-19 ____1ZZBADTEST 37j PaeeSensingTransformer12.2-19 J_____BADReplaceTransformerTESTCHECK CUSTO

SECTION 2.2DIAGNOSTIC TESTSTEST 1-15 AMPFUSERemove and visually inspect the 15 Amp Fuse. Replace, if Fuse element has melted. A more thorough check ma

TEST3-ST0P/START SWITCHLeft Hand10 (Ground)Remove 15 Amp Fuse to disconnect starting circuit. Remove panel top cover. Disconnect wires from switch ter

RESULTS:- Solenoid actuates, enginedoes not crank...Continue tests in Paragraph BSolenoid does not actuate.•...Continue tests in Paragraph

TEST 6-STARTER DRIVE GEARA.)-Hold Stop/Start switch at its START position and listen for the starter motor. If motor runs freely (without load), remo

TEST 9-OIL MAKE-UP TANKCheck oil level in Oil Make-Up Tank. If oil level is below OIL CHANGE LEVEL arrows, fill tank with recommended engine oil and r

TEST 12- IGNITION MODULEUnplug the Ignition Module from its receptacle on the side of the stator can. Carefully inspect module and receptacle pins fo

RESULTS;— Meter needle does not move«Meter indicates approximately 250. Ohms..Check Wire No, 8, between Ignition Module receptacle and Ignition Stator

PART I GENERALSection 1.1 1.1.1 1.1.21.1.31.1.4 • 1.1.51.1.6Section 1.2 Section 1.3SPECIFICATIONS Model Numbers Fuels and OilsTorque Specifications (G

TEST 15:- LOW FUELThe motor home engine and the alternator engine should "share” the vehicle fuel tank, through a dual fuel pickup tube arrangem

TEST 18;- PRINTED CIRCUIT BOARDA.)- Depress Printed Circuit Board connector plug locking tangs and remove connector plug. On the connector plug, loca

TEST 20;- FUEL LOCK-OFF SOLENOIDA.)- Locate Wire No. 14 between the Fuel Lock-Off Solenoid and terminal strip. Disconnect the wire at its terminal str

C.)- Check Wire No. 14, between Fuel Pump and terminal strip, for open or shorted condition,RESULT:- Wire No. 14 checks good...Continue Diagn

A.)-Turn High Speed Jet Adjusting Screw clockwise until it just bottoms. DO NOT USE EXCESSIVE FORCE. Then turn High Speed Jet Adjusting Screw counter

RESULT:- Float Valve, Seat, Gasket andFloat level are good...Float Valve, Seat, Gasket or Float level check bad...-...Continue Diagnostic T

TEST 26:- VALVESRemove valves. Clean all parts in non-flammable solvent. Remove all carbon. Replace damaged or distorted valves. If valves are useabl

Timing is established at 21 BTDC by the physical location of the magnet on the fan. Thus any damage that results in a physical change in the magnet&ap

D.)-Set VOM to ”+DC'’ and to ”50V.” scale. Connect the positive (+) meter test probe to the Wire No. 91 terminal on the choke solenoid and the re

A.)- Adjust Carburetor as outlined in Test 23, The Carburetor must be adjusted BEFORE attempting to adjust the Governor,RESULT Problem is corrected...

SECTION 1.1SPECIFICATIONS1.1.T-M0DEL NUMBERSModel No,MC-356894MC-356895MC-386938MC-38 69 39MC-406896MC-40 6897 ..Wattage Capacitv3500 3500 38003800 40

TEST 34:- EXCITATION WINDINGSRemove the assembly.alternator front panelDisconnect the white connector plug from its receptacle on the stator can. On t

TEST 36:- CHECK VOLTAGEDisconnect customer wiring from Wires No. T1 and T2 in alternator connection box. Check a-c voltage output at Wire No. T1 and j

RESULT:- Primary windiag rasistance. checks good..Check customer wiring Primary winding resistance is bad,...Replace TransformerNOTEThe Sensing Tr

rotor checks bad in Paragraph A, check Wires No. 1 and 4 for an open or shorted condition. Inspect brushes - replace if cracked, chipped or less than

TEST 41:-CHECK STATORA.)- Set VOM to ”+DC" and to ”Rxl” scale, then zero the meter. Connect meter test probes to Pins 1 and 2 of red receptacle o

SECTION 2.3BATTERY CHARGE CIRCUITCHARRING CURRENTTESTS1,)- Plug the black (-) test lead into the "-10A" jack on the VOM. Plug the red (+) te

DIODES D1 ANDD2A.)- Disconnect Wire No. 78 at the circuit breaker CB-2, Set the VOM to '*+DC” and to ’’Rxl” scale. Zero the meter. Connect the po

2.4.1-GENERALSECTION 2.4MODEL 6897-42.4.1.1-INTRODUCTIONThe Model 6897-4 (MC-40) alternator incorporates several new components in its DC control syst

2.4.1.4-FIELD BOOST MODULE (FB)Many alternators rely on residual or ’’stored" magnetic energy to provide the initial magnetic field around the ro

2.4.2.2-CRANKINGthe 15 Amp Fuse, Wire No. 15, the Starter Contactor (SC), and Wire No. 17. When the Stop/Stairt Sx<rLtch is set to START position,,

1.1.3- TORQUE SPECIFICATIONS (GENERAL)STANDARD TORQUE VALUESAll Values in FOOT-POUNDSGrade 2Grade 5Grade 7Grade 8BOLT SIZEDRY LUBDRYLUBDRY LUBDRY LUB1

2.4.2.3- RUNNINGReleasing the Stop/Start Switch to NEUTRAL opens the DC circuit from the battery. Wire No. 13, 15 Amp Fuse, Wire No. 15, Starter Conta

When the Stop/Start Switch is set to STOP, Ignition Stator (IS) output from Wire No. 25, Ignition Module (IM) Pin No. 3, Wire No. 25 to the Terminal B

Refer to 2.4.1,3 and 2,4.2, this Section, If engine starts and then shuts down, the problem may be caused by the Control Relay (CR). Proceed as follo

B,)-Set VOM to ”+DC” and to any scale that will permit 12 Volts to be read. Connect the positive meter test probe to the Wire No. 4 connection at Fie

PART IIIDISASSEMBLY &REPAIRSection 3.13.1.13.1.23.1.3Section 3.23.2.13.2.23.2.3Section 3.3 3.3.1 '3.3.23.3.3BLOWER SHROUD SECTION Disassembly

SECTION 3.1BLOWER SHROUD SECTION3.1.1-D1SASSEM<^LY3.1 .1 .1 -IT.sp R 5/16 Inch nut driver to remove screws and flat washers Chat retain blower shro

2#_l_Ll2_6-Use a lO nim \^пгRт^ch to remove blower, scroll bolts nearest the pngine taper shaft. The bolt at lower right comer of blo

3.1.2-INSPECTION AND REPAIRClean and degrease all components, including sheet metal* Inspect all parts as follows1*)- Carefully check all sheet metal

3.1» 3,4-Loosoly retain blower housing support to opposite vibration damper with capscrew, lockwasher and flatwasher.3,1,3,6-Slide exhaust pipe down

3^1,3>9-Align keyway in blower fan hub wlCh drive key on engine shaft. Install blower fan over engine shaft. Make sxire drive key and keyway are e

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SECTION 3.2ALTERNATOR SECTION3.2.1-DISASSEMBLY3#2»1«1-At the terminal strip, disconnect Che Wire No. 20 chat comes Truiu the low oil le

3.2,1,7~St:raighCpn brush holdei' locking tangs on bearing carrier, Kemove brush holder from carrier. Remove brush leads from brushes and remove

3»2., 1« 13-Remove starter cable atthe starter terminal.3.2.1.15-At the terminal strip, disconnect the wire from the fuel lockoff solenoid.3.2.1.14-Cu

3,2,1,20~SelQcc a stud from the kit that is long enough so that, when the stud is threaded into the engine crankshaft, the slotted end of the stud wi

3,2,2,2- BRUSH HOLDER AND BRUSHESReplace brush holder if cracked or otherwise damaged. Replace brushes if cracked, chipped or less than 5/16 inch lon

3> 2,3« 2"Ignition scacor mouncing holes are offset to make improper Installation difficult. Install the ignition stator and retain with No. 1

3¿_2jj_3_2_7-Align adapter casting with bolt holes in engine gear cover. Install casting, making sure the carburetor intake manifold studs are aligned

1.2*3, ll-CoiuifeicL Wire No, 14 (the longest vTire) from the fuel lock- off solenoid Co Lhe termtnal strip. Refer to appropriate wiring diagram for w

n pane.l dividpr to stator can with two taptite screws. The ground wire (No. 10) previously disconnected from Stop/Start switch ter-3.Z.ii. 1 / -Ins

3.2.3.20-Connecc 2 red wires (No. 3,2.3.21-Sllde brush holder lock-A) to brush that will he nearest Che rotor bearing. Retain \^th a No, 6-32 Sims scr

1.1.6-ENGINE SPECIFICATIONSINCHES METRICSpark Plug Gap0.0350.009 mmValve Spring Length1.2995 33.000 mmValve Spring Compression Length1.023626.000 mmVa

3« 2» 3,24-Install rpar panel with voltage regulator. Connect read and white connector plugs into their receptacles. Install front panel• Connect grou

SECTION 3.3ENGINE SECTION3.3.1- DISASSEMBLY3.3.1. l-Dlsconnect. governor spring from governor adjusting screw. Loosen governor arm'clamp bole an

3,3*1« 7-Remove 8 cylinder head uuts. Remove cylinder head and head gasket:«3,3«l,9~Use valve spring compressor Co compress valve springs. Then r

3,3,l.l2-RGmovc governor slider from 3.3.1.13-Remove cam shaft and valve end of cam shaft. tappets*3* 3*1*14-Bend lock Cab ends away from con

3.3.1.17-Remove governor shafL retaining clip and governor shaft.3.3.1.19-Remove bolts that retain counterbalance cover.3.3.1.21-Remove counterba

3.3.2- INSPECTION AND REPAIR3.3.2.1- CYLINDER BLOCKReplace cylinder block i£:-a. )-Fins are broken or crackedb. )-Head mounting surface is warpedc.

3.3.2.5-PISTONmeasure pistonPiston diameter 3.067”-3.068”Clean carbon from piston ring grooves, as well as from upper cylinder bore and head» Check p

CTLINCWPISTON ,pi3TON RingCheck ring gaps on worn rings to determine if rings should be replaced. Check gaps on new rings to determi

1. )- Rotate crankshaft until piston is at top dead center (TlX:) of itscompression stroke.2. )- Insert valves in their guides and hold them firmly

3* 3« 3« 8-Connecting rod and connecting rod cap are a matched set and must be replaced as a set. Mark on cap (see above) must align with identical

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3.3«3>lO-TnsLa11 tappets*3*3*3*12-InsCall thrust washer over end of camshaft.3.3» 3.14-Install one of the longer bolts that retained the engine ge

3» .1, 3« 1 5-Insfa 11 a new gear cover gasket*if a3.3* 3*17-Install the correct bolt and fiat washer into counterbalance alignment hole* USE THE COE

3« 3> 3» 20-Install springs and retainers over tappets. Intake valve is identified by the letter ”1", exhaust valve by an Slideboth velves d

3.3.3> 25-InsCall new intake manifold elbow gasket- Install Intake manifold elbow.3,3-3,26-Instail spark plug. Cap should he set to O.Ol^ Inch

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