Generac GP1800, GP3250, GP5000, GP5500, GP6500 Service Manual

MANUALEQUIPOSPESADOS.COM

®

Diagnostic

Repair

Manual

GP Series Portable Generators

MODELS:

GP1800

GP3250

GP5000

GP5500

GP6500

GP7000

GP8000

P o r t a b l e g e n e r a t o r s

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SAFETY

Throughout this publication, “DANGER!” and “CAUTION!” blocks are used to alert the mechanic to special instructions concerning a particular service or operation that might be hazardous if performed incorrectly or carelessly. PAY CLOSE ATTENTION TO THEM.

*DANGER! UNDER THIS HEADING WILL BE FOUND SPECIAL INSTRUCTIONS WHICH, IF NOT COMPLIED WITH, COULD RESULT IN PERSONAL INJURY OR DEATH.

*CAUTION! Under this heading will be found special instructions which, if not complied with, could result in damage to equipment and/or property.

These “Safety Alerts” alone cannot eliminate the hazards that they signal. Strict compliance with these special instructions plus “common sense” are major accident prevention measures.

NOTICE TO USERS OF THIS MANUAL

This SERVICE MANUAL has been written and published by Generac to aid our dealers' mechanics and company service personnel when servicing the products described herein.

It is assumed that these personnel are familiar with the servicing procedures for these products, or like or similar products manufactured and marketed by Generac. That they have been trained in the recommended servicing procedures for these products, including the use of common hand tools and any special Generac tools or tools from other suppliers.

Generac could not possibly know of and advise the service trade of all conceivable procedures by which a service might be performed and of the possible hazards and/or results of each method. We have not undertaken any such wide evaluation. Therefore, anyone who uses a procedure or tool not recommended by Generac must first satisfy themselves that neither his nor the products safety will be endangered by the service procedure selected.

All information, illustrations and specifications in this manual are based on the latest product information available at the time of publication.

When working on these products, remember that the electrical system and engine ignition system are capable of violent and damaging short circuits or severe electrical shocks. If you intend to perform work where electrical terminals could be grounded or touched, the battery cables should be disconnected at the battery.

Any time the intake or exhaust openings of the engine are exposed during service, they should be covered to prevent accidental entry of foreign material. Entry of such materials will result in extensive damage when the engine Is started.

During any maintenance procedure, replacement fasteners must have the same measurements and strength as the fasteners that were removed. Metric bolts and nuts have numbers that indicate their strength. Customary bolts use radial lines to indicate strength while most customary nuts do not have strength markings. Mismatched or incorrect fasteners can cause damage, malfunction and possible injury.

REPLACEMENT PARTS

Components on Generac recreational vehicle generators are designed and manufactured to comply with Recreational Vehicle Industry Association (RVIA) Rules and Regulations to minimize the risk of fire or explosion. The use of replacement parts that are not in compliance with such Rules and Regulations could result in a fire or explosion hazard. When servicing this equipment, it is extremely important that all components be properly installed and tightened. If improperly installed and tightened, sparks could ignite fuel vapors from fuel system leaks.

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Specifications...........................................................	2
Part 1 – General Information...................................	9
Section 1.1 – Generator Fundamentals.................	10
Magnetism........................................................	10
Electromagnetic Fields.....................................	10
Electromagnetic Induction................................	10
A Simple AC Generator....................................	11
A More Sophisticated AC Generator................	11
Section 1.2 – Measuring Electricity.......................	13
Meters .............................................................	13
The VOM..........................................................	13
Measuring AC Voltage......................................	13
Measuring DC Voltage......................................	13
Measuring AC Frequency.................................	13
Measuring Current............................................	14
Measuring Resistance......................................	14
Electrical Units..................................................	15
Ohm's Law........................................................	15
Section 1.3 – Brushless, Capacitor
Excitation System............................	16
Introduction.......................................................	16
Stator Assembly...............................................	16
Rotor Assembly................................................	16
Circuit Breakers................................................	16
Operation..........................................................	17
Section 1.4 – Brushed Excitation System..............	18
Introduction.......................................................	18
Stator Assembly...............................................	18
Brush Holder and Brushes...............................	18
Rotor Residual Magnetism...............................	18
Voltage Regulator.............................................	18
Operation..........................................................	18
Section 1.5 – Testing, Cleaning and Drying...........	20
Insulation Resistance.......................................	20
The Megohmmeter...........................................	20
Stator Insulation Resistance Test.....................	20
Cleaning the Generator....................................	21
Drying the Generator........................................	21
Part 2 – AC Generators..........................................	21
Section 2.1 – Brushless Capacitor
Troubleshooting Flowcharts.............	22
Section 2.2 – Brushed Excitation
Troubleshooting Flowcharts.............	24
Section 2.3 – AC Diagnostic Tests.........................	26
Introduction.......................................................	26
Test 1 – Check No-Load Voltage
and Frequency.....................................	26
Test 2 – Check Circuit Breaker.........................	26
Test 3 – Check Continuity of
Receptacle Panel.................................	26

Test 4 – Field Flash Alternator
(Configuration “A” Only).......................	27
Test 5 – Check Brushed Rotor Circuit..............	28
Test 6 – Check Capacitor.................................	29
Test 7 – Test Brushless DPE Winding..............	30
Test 8 – Test Brushless Stator Windings..........	30
Test 9 – Test Brushed Stator Windings.............	31
Test 10 – Check Load Voltage & Frequency.....	31
Test 11 – Check Load Watts & Amperage........	31
Test 12 – Adjust Voltage Regulator...................	31
Part 3 – Engine Troubleshooting...........................	33
Section 3.1 – 389/206/163cc Troubleshooting
Flowcharts........................................	34
Section 3.2 – 410cc Troubleshooting Flowcharts.. 37
Section 3.3 – Diagnostic Tests...............................	42
Test 20 – Check 1.5 Amp Fuse........................	42
Test 21 – Check Battery & Cables....................	42
Test 22 – Check Voltage at
Starter Contactor (SC).........................	42
Test 23 – Check Start-Run-Stop Switch...........	42
Test 24 – Test OFF-ON Switch.........................	43
Test 25 – Check Starter Motor..........................	43
Test 25 – Check Ignition Spark.........................	45
Test 26 – Check Spark Plugs...........................	46
Test 29 – Check Carburetion............................	46
Test 30 – Choke Test........................................	47
Test 33 – Check Valve Adjustment...................	47
Test 36 – Check Engine / Cylinder Leak Down
Test / Compression Test.......................	48
Test 38 – Check Flywheel.................................	48
Test 39 – Remove Wire 18 / Shutdown Lead....	49
Test 40 – Check / Adjust Governor
(389cc Engine).....................................	49
Test 41 – Check / Adjust Governor
(410cc Engine).....................................	50
Test 45 – Check Oil Level Switch.....................	51
Test 46 – Check Oil Pressure Switch...............	51
Test 49 – Test Recoil Function..........................	52
Test 50 – Test Engine Function.........................	52
Part 4 – Disassembly.............................................	53
Section 4.1 – Major Disassembly..........................	54
Part 5 – Electrical Data..........................................	71
Electrical Schematic, GP1850...............................	72
Electrical Schematic, GP3250...............................	73
Electrical Schematic, GP5000/5500/GP6500........	74
Wiring Diagram, GP5000/5500/GP6500...............	75
Electrical Schematic, GP7000E/GP8000E............	76
Wiring Diagram, GP7000E/GP8000E....................	77
Electrical Formulas................................................	78

Page 1

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Specifications – GP1800

	M
H	A

Outlets

A (2) 5-20R 120V

Circuit Breakers

M	(1) 20A

Other Features

H On/Off Switch

Product Series	GP1800
A/C Rated Output Watts:	1800
A/C Maximum Output Watts:	2050
A/C Voltage	120VAC
A/C Frequency	60 Hz
Rated 120 VAC Amperage	7.5
Max 120 VAC Amperage	8.5
Engine Displacement	163cc
Engine Type	OHV
Engine RPM	3600
Recommended Oil	5W30
Lubrication Method	Splash Sump
Choke Type	Manual Lever
Fuel Shut Off	Manual Lever
Idle Control	Full Speed
Starting Method	Manual
Battery	n/a
Battery Size	n/a
Low Oil Shutdown Method	Low Level
Start Switch Type	On/Off Toggle
Switch Location	Control Panel
Single-Point Lifting Eye	N/A
Fuel Gauge	Built-In
Fuel Tank Capacity (Gal)	4
Fuel Tank Capacity (Liters)	15.14
Run Time at 50% (Hours)	14
Cord Set	No
Handle Style	Folding
Wheel type	n/a
Length (L)	23.5
Width (W)	17
Height (H)	17.5
Extended Length (EL)	23.5
Unit Weight (lbs)	79
Spark Plug Type	NGK BPR4ES
	or Champion
	RN14YC
Spark Plug Gap	0.028"-0.031"
	(0.7-0.8mm)
Oil Capacity	0.634 quart
	(0.6 liter)

Page 2

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Specifications – GP3250

Product Series	GP3250
A/C Rated Output Watts:	3250
A/C Maximum Output Watts:	3750
A/C Voltage	120VAC
A/C Frequency	60 Hz
Rated 120 VAC Amperage	13.5
Max 120 VAC Amperage	15.6
Engine Displacement	206cc
Engine Type	OHV
Engine RPM	3600
Recommended Oil	5W30
Lubrication Method	Splash Sump
Choke Type	Manual Lever
Fuel Shut Off	Manual Lever
Idle Control	Full Speed
Starting Method	Manual
Battery	n/a
Battery Size	n/a
Low Oil Shutdown Method	Low Level
Start Switch Type	On/Off Toggle
Switch Location	Control Panel
Single-Point Lifting Eye	N/A
Fuel Gauge	Built-In
Fuel Tank Capacity (Gal)	4
Fuel Tank Capacity (Liters)	15.14
Run Time at 50% (Hours)	13.5
Cord Set	No
Handle Style	Folding
Wheel type	7.0" Solid Wheels
Length (L)	25.5
Width (W)	21
Height (H)	19
Extended Length (EL)	39.5
Unit Weight (lbs)	91
Spark Plug Type	NGK BPR4ES
	or Champion
	RN14YC
Spark Plug Gap	0.028"-0.031"
	(0.7-0.8mm)
Oil Capacity	0.634 quart
	(0.6 liter)

		M
	H	A
Outlets
A	(4) 5-20R 120V

Circuit Breakers

M	(2) 20A

Other Features

H On/Off Switch

Page 3

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Specifications – GP5000

				Product Series	GP5000
				A/C Rated Output Watts:	5000
				A/C Maximum Output Watts:	6250
				A/C Voltage	120/240VAC
				A/C Frequency	60 Hz
				Rated 120/240 VAC Amperage	20.8
				Max 120/240 VAC Amperage	26.0
				Engine Displacement	389cc
				Engine Type	OHV
				Engine RPM	3600
				Recommended Oil	5W30
				Lubrication Method	Splash Sump
		A		Choke Type	Manual Lever
B			H	Fuel Shut Off	Manual Lever
				Idle Control	Full Speed
				Starting Method	Manual
				Battery	n/a
				Battery Size	n/a
				Low Oil Shutdown Method	Low Level
				Start Switch Type	3-Position
				Switch Location	On Engine
				Single-Point Lifting Eye	N/A
N	M			Fuel Gauge	Built-In
Receptacles				Fuel Tank Capacity (Gal)	6.6
				Fuel Tank Capacity (Liters)	24.981
A		(4) 5-20R 120V
				Run Time at 50% (Hours)	10
B	L14-30R Twist-Lock 120/240V
				Cord Set	No
Circuit Breakers				Handle Style	Folding Interlocked
				Wheel type	9.5" Solid Wheels
M		(2) 20A
				Length (L)	33.5
N		(2) 25A
				Width (W)	26.5
Other Features				Height (H)	27.5
H		Hour Meter with		Extended Length (EL)	47
	Maintenance Reset
				Unit Weight (lbs)	167
				Spark Plug Type	NHSP F7RTC or
					Champion RN9YC
				Spark Plug Gap	0.028"-0.031"
					(0.7-0.8mm)
				Oil Capacity	1.16 quart
					(1.1 liter)

Page 4

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Specifications – GP5500

Product Series	GP5500
A/C Rated Output Watts:	5000
A/C Maximum Output Watts:	6875
A/C Voltage	120/240VAC
A/C Frequency	60 Hz
Rated 120/240 VAC Amperage	22.9
Max 120/240 VAC Amperage	28.6
Engine Displacement	389cc
Engine Type	OHV
Engine RPM	3600
Recommended Oil	5W30
Lubrication Method	Splash Sump
Choke Type	Manual Lever
Fuel Shut Off	Manual Lever
Idle Control	Full Speed
Starting Method	Manual
Battery	n/a
Battery Size	n/a
Low Oil Shutdown Method	Low Level
Start Switch Type	3-Position
Switch Location	On Engine
Single-Point Lifting Eye	N/A
Fuel Gauge	Built-In
Fuel Tank Capacity (Gal)	6.6
Fuel Tank Capacity (Liters)	24.98
Run Time at 50% (Hours)	10
Cord Set	No
Handle Style	Folding Interlocked
Wheel type	9.5" Solid Wheels
Length (L)	33.5
Width (W)	26.5
Height (H)	27.5
Extended Length (EL)	47
Unit Weight (lbs)	167
Spark Plug Type	NHSP F7RTC or
	Champion RN9YC
Spark Plug Gap	0.028"-0.031"
	(0.7-0.8mm)
Oil Capacity	1.16 quart
	(1.1 liter)

B A H

	N	M
	Receptacles
	A	(4) 5-20R 120V
	B
		L14-30R Twist-Lock 120/240V
	Circuit Breakers
	M	(2) 20A
	N
		(2) 25A
	Other Features
	H	Hour Meter with
		Maintenance Reset

Page 5

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Specifications – GP6500

			Product Series	GP6500
			A/C Rated Output Watts:	6500
			A/C Maximum Output Watts:	8000
			A/C Voltage	120/240VAC
			A/C Frequency	60 Hz
			Rated 120/240 VAC Amperage	27.1
			Max 120/240 VAC Amperage	33.3
			Engine Displacement	389cc
			Engine Type	OHV
			Engine RPM	3600
			Recommended Oil	5W30
			Lubrication Method	Splash Sump
B	A	H	Choke Type	Manual Lever
			Fuel Shut Off	Manual Lever
			Idle Control	Full Speed
			Starting Method	Manual
			Battery	n/a
			Battery Size	n/a
			Low Oil Shutdown Method	Low Level
			Start Switch Type	3-Position
			Switch Location	On Engine
N	M		Single-Point Lifting Eye	N/A
			Fuel Gauge	Built-In
Outlets			Fuel Tank Capacity (Gal)	6.6
A	(4) 5-20R 120V		Fuel Tank Capacity (Liters)	24.98
B	L14-30R Twist-Lock 120/240V		Run Time at 50% (Hours)	9
Circuit Breakers			Cord Set	No
			Handle Style	Folding Interlocked
M	(2) 20A
			Wheel type	9.5" Solid Wheels
N	(2) 30A
			Length (L)	33.5
Other Features			Width (W)	26.5
H	Hour Meter with Maintenance Reset		Height (H)	27.5
			Extended Length (EL)	47
			Unit Weight (lbs)	172
			Spark Plug Type	NHSP F7RTC or
				Champion RN9YC
			Spark Plug Gap	0.028"-0.031"
				(0.7-0.8mm)
			Oil Capacity	1.16 quart
				(1.1 liter)

Page 6

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Specifications – GP7000/GP7000E

Product Series	GP7000
A/C Rated Output Watts:	7000
A/C Maximum Output Watts:	8750
A/C Voltage	120/240VAC
A/C Frequency	60 Hz
Rated 120/240 VAC Amperage	29.2
Max 120/240 VAC Amperage	36.5
Engine Displacement	410cc
Engine Type	OHVI
Engine RPM	3600
Recommended Oil	5W30
Lubrication Method	Full Pressure
Choke Type	Manual Lever
Fuel Shut Off	Manual Lever
Idle Control	Full Speed
Starting Method GP7000	Manual
Starting Method GP7000E	Manual or Electric
Battery Size (if equipped)	12VDC 10 Ahr
Low Oil Shutdown Method	Low Pressure
Start Switch Type	3-Position
Switch Location	On Engine
Single-Point Lifting Eye	N/A
Fuel Gauge	Built-In
Fuel Tank Capacity (Gal)	8
Fuel Tank Capacity (Liters)	30.28
Run Time at 50% (Hours)	11
Cord Set	No
Handle Style	Folding Interlocked
Wheel type	9.5" Solid Wheels
Spark Plug Type	Champion RC14YC
Spark Plug Gap	0.030" (0.76mm)
Oil Capacity	1.5 quart w/filter

B A H

N M

Outlets

A(4) 5-20R 120V

BL14-30R Twist-Lock 120/240V

Circuit Breakers

M	(2) 20A
N
	(2) 30A

Other Features

H Hour Meter with Maintenance Reset

Page 7