Generac Power Systems Pro ST47019GENG User manual

Owner’s Manual
Stump Grinder
SAVE THIS MANUAL FOR FUTURE REFERENCE
MODEL NUMBER: _________________________
SERIAL NUMBER: _________________________
DATE PURCHASED:________________________
005812
Register your Generac product at:
WWW.GENERAC.COM
1-888-GENERAC
(888-436-3722)

ii Owner’s Manual for Stump Grinder
(000393a)
WARNING
CANCER AND REPRODUCTIVE HARM
www.P65Warnings.ca.gov.

Owner’s Manual for Stump Grinder iii
Table of Contents
Section 1: Safety Rules & General
Information
Introduction ..................................................................1
Read This Manual Thoroughly ....................................1
Safety Rules .................................................................1
How to Obtain Service .................................................1
General Hazards ...........................................................2
Exhaust and Fuel Hazards ..........................................2
Fire Hazards .................................................................3
Explosion Hazards .......................................................3
Safety and Operating Decals ......................................4
Section 2: General Information and Setup
Emissions .....................................................................5
Remove Contents from Carton ...................................6
Assembly Instructions ................................................7
Maintenance Meter Installation .................................10
Attaching Manual Caddy ...........................................10
Installing Tow Hitch Kit .............................................10
Installing Tow Bar Adapter ........................................10
Assembling Hitch Adapter .........................................11
Assembling Trailer Hitch ...........................................11
Adding Oil ...................................................................11
Adding Fuel ................................................................12
Connecting Battery Cable .........................................12
Checking Tire Pressure .............................................12
Hitching Unit to Tow Vehicle ....................................13
Hitch Adapter .............................................................13
Trailer Hitch ...............................................................13
High Altitude Replacement Kit ..................................14
Section 3: Operation
Operation and Use Questions ..................................15
Controls and Symbols ...............................................15
Starting Engine ..........................................................15
Manual Starting .........................................................15
Electric Starting .........................................................16
Stopping Engine ........................................................16
Grinding the Stump ...................................................16
Section 4: Maintenance and
Troubleshooting
Maintenance ...............................................................19
Operating Maintenance Meter ...................................20
Air Filter Maintenance ...............................................20
Changing Engine Oil ..................................................20
Servicing Spark Plug .................................................21
Lubricating Cables .....................................................21
Replacing Belt ............................................................21
Replacing Clutch ........................................................22
Rotating Cutting Teeth ..............................................22
Replacing Cutting Teeth ............................................23
Adjusting Handlebars ................................................23
Replacing Wheels ......................................................24
Adjusting Brake .........................................................24
Tightening Brake Cable .............................................24
Loosening Brake Cable .............................................24
Ball Hitch Receiver Adjustment ................................24
Ball Hitch Receiver Adjustment Check ......................24
Ball Hitch Receiver Adjustment .................................25
Battery Care ...............................................................25
Charging Battery .......................................................25
Replacing Battery ......................................................26
Troubleshooting .........................................................26

iv Owner’s Manual for Stump Grinder
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Safety Rules & General Information
Owner’s Manual for Stump Grinder 1
Section 1: Safety Rules & General Information
Introduction
Thank you for purchasing a Generac Power Systems Inc.
product. This unit has been designed to provide high
performance, efficient operation, and years of use when
maintained properly.
The information in this manual is accurate based on
products produced at the time of publication. The
manufacturer reserves the right to make technical
updates, corrections, and product revisions at any time
without notice.
Read This Manual Thoroughly
If any section of this manual is not understood, contact
Generac Customer Service at 1-888-436-3722 (1-888-
GENERAC), or www.generac.com with any questions
or concerns.
This manual must be used in conjunction with the
appropriate installation manual.
SAVE THESE INSTRUCTIONS: The manufacturer
suggests that this manual and the rules for safe operation
be copied and posted near the unit installation site.
Safety should be stressed to all operators and potential
operators of this equipment.
Safety Rules
The manufacturer cannot anticipate every possible cir-
cumstance that might involve a hazard. The alerts in this
manual, and on tags and decals affixed to the unit, are
not all inclusive. If using a procedure, work method, or
operating technique that the manufacturer does not spe-
cifically recommend, verify that it is safe for others and
does not render the equipment unsafe.
Throughout this publication, and on tags and decals
affixed to the unit, DANGER, WARNING, CAUTION, and
NOTE blocks are used to alert personnel to special
instructions about a particular operation that may be
hazardous if performed incorrectly or carelessly. Observe
them carefully. Alert definitions are as follows:
NOTE: Notes contain additional information important to
a procedure and will be found within the regular text of
this manual.
These safety alerts cannot eliminate the hazards that
they indicate. Common sense and strict compliance with
the special instructions while performing the action or
service are essential to preventing accidents.
How to Obtain Service
When the unit requires servicing or repairs, contact
Generac Customer Service at 1-888-436-3722 (1-888-
GENERAC), or www.generac.com for assistance.
When contacting Customer Service about parts and
service, always supply the complete model and serial
number of the unit as given on its data decal located on
the unit. Record the model and serial numbers in the
spaces provided on the inside front cover of this manual.
(000100a)
WARNING
Consult Manual. Read and understand manual
completely before using product. Failure to
completely understand manual and product
could result in death or serious injury.
(000001)
DANGER
Indicates a hazardous situation which, if not avoided,
will result in death or serious injury.
(000002)
WARNING
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
(000003)
CAUTION
Indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.

Safety Rules & General Information
2Owner’s Manual for Stump Grinder
General Hazards
Exhaust and Fuel Hazards
(000130)
WARNING
Accidental Start-up. Disconnect the negative battery
cable, then the positive battery cable when working
on unit. Failure to do so could result in death
or serious injury.
(000128a)
Personal injury. Keep out of reach of children.
Failure to do so could result in death or serious injury.
WARNING
(000377)
WARNING
Vision loss. Eye protection is required when
servicing unit. Failure to do so could result in
vision loss or serious injury.
WARNING
Personal injury and equipment damage. Do not
tamper with engine governed speed. Operating
engine too fast or slow increases the risk of injury
or permanent engine damage. (000254)
(000115)
WARNING
Moving Parts. Do not wear jewelry when
starting or operating this product. Wearing
jewelry while starting or operating this product
could result in death or serious injury.
(000111)
WARNING
Moving Parts. Keep clothing, hair, and
appendages away from moving parts. Failure
to do so could result in death or serious injury.
(000108)
WARNING
Hot Surfaces. When operating machine, do not
touch hot surfaces. Keep machine away from
combustibles during use. Hot surfaces could
result in severe burns or fire.
(000110)
WARNING
Risk of Fire. Hot surfaces could ignite
combustibles, resulting in fire. Fire could
result in death or serious injury.
WARNING
Risk of injury. Do not operate or service this machine
if not fully alert. Fatigue can impair the ability to service
this equipment and could result in death or serious
injury. (000215)
WARNING
Environmental Hazard. Always recycle batteries at an
official recycling center in accordance with all local
laws and regulations. Failure to do so could result in
environmental damage, death or serious injury.
(000228)
(000107)
WARNING
Hearing Loss. Hearing protection is
recommended when using this machine.
Failure to wear hearing protection could
result in permanant hearing loss.
WARNING
(000492)
Personal injury. Wear sturdy shoes with no-slip tread,
long pants, and gloves when operating this unit.
Failure to do so could result in death or serious injury.
Asphyxiation. Running engines produce
carbon monoxide, a colorless, odorless,
poisonous gas. Carbon monoxide, if not
avoided, will result in death or serious injury.
(000103)
DANGER
(000143)
DANGER
Explosion and Fire. Fuel and vapors are extremely
flammable and explosive. Store fuel in a well
ventilated area. Keep fire and spark away. Failure
to do so will result in death or serious injury.
(000166b)
DANGER
Explosion and Fire. Do not overfill fuel tank. Fill to
1/2 inch from top of tank to allow for fuel expansion.
Overfilling may cause fuel to spill onto engine causing
fire or explosion, which will result in death or
serious injury.

Safety Rules & General Information
Owner’s Manual for Stump Grinder 3
Fire Hazards
Explosion Hazards
(000174)
DANGER
Risk of fire. Allow fuel spills to completely dry
before starting engine. Failure to do so will
result in death or serious injury.
WARNING
Fire risk. Fuel and vapors are extremely
flammable. Do not operate indoors. Doing so
could result in death, serious injury, or
property or equipment damage. (000281)
WARNING
Explosion and fire risk. Do not smoke near unit.
Keep fire and spark away. Failure to do so could
result in death, serious injury, or property or
equipment damage. (000282)
WARNING
Explosion and Fire. Do not smoke while
refueling unit. Failure to do so could result in
death, serious injury, or property or equipment
damage. (000284a)
(000109)
WARNING
Risk of Fire. Verify machine has properly
cooled before installing cover and storing
machine. Hot surfaces could result in fire.
Risk of fire. Never operate engine without
the air cleaner installed. Operating engine
without the air cleaner could result in death
or serious injury.
WARNING
(000249)
(000192)
DANGER
Explosion and fire. Fuel and vapors are extremely
flammable and explosive. No leakage of fuel is
permitted. Keep fire and spark away. Failure to do
so will result in death or serious injury.
(000174)
DANGER
Risk of fire. Allow fuel spills to completely dry
before starting engine. Failure to do so will
result in death or serious injury.
(000110)
WARNING
Risk of Fire. Hot surfaces could ignite
combustibles, resulting in fire. Fire could
result in death or serious injury.

Safety Rules & General Information
4Owner’s Manual for Stump Grinder
Safety and Operating Decals
This unit features numerous safety and operating decals. These decals provide important operating instructions and
warn of dangers and hazards. Replace damaged or missing safety and operating decals immediately.
008060
006079
006081
008056
008059
006705
006009
008058
006078
008055
008057
006002

Owner’s Manual for Stump Grinder 5
General Information and Setup
Section 2: General Information and Setup
Figure 2-1. Features and Controls
A complete specification sheet is included in the
documentation provided with the unit at the time of
purchase. For additional copies, contact Generac
Customer Service at 1-888-436-3722 (1-888-
GENERAC), or www.generac.com.
Emissions
The United States Environmental Protection Agency (US
EPA) (and California Air Resources Board (CARB), for
engines/equipment certified to California standards)
requires that this engine/equipment complies with
exhaust and evaporative emissions standards. Locate the
emissions compliance decal on the engine to determine
applicable standards. For emissions warranty information,
reference the included emissions warranty. It is important
to follow the maintenance specifications in the manual to
ensure that the engine complies with the applicable emis-
sions standards for the duration of the product’s life.
005812
006533
L
D
C
A
AThrottle Lever
BStart Key Switch
CGas Fill
DOil Drain
EBelt Guard
FOperator Presence Lever
GBrake Lever
HOil Fill/Check
B
K
I
F
G
H
E
J
ICarbide Teeth
JStarter Cord
KFuel Shut-Off
LChoke Lever
Stump Grinder Specifications
Tire Size 14.5 in (36.83 cm) pneumatic
Handle Bars (in/cm) Height adjustable 32 (81.28),
36.5 (92.71), 40 (101.6)
Brake Band w/locking feature
Brake Diameter 4 in (10.6 cm)
Clutch Centrifugal
Clutch Engagement
Speed 1900 RPM
Frame Welded 12 ga steel construction
Belt V-belt
Belt Size (in/cm) AP47: 49.8 (126.49) OD,
47.3 (120.14) ID
Belt Construction Wrapped for abrasion resistance
Cutting Head Rotary 8 tooth
Cutting Head Size w/
teeth (in/cm)
1.75 (4.44) wide X 10.5 (26.67)
diameter
Cutting Teeth Replaceable carbide tipped
(three position)
Machine Dimensions
W X L X H (in/cm)
28 (72.12) X 51 (129.54) X
36 (91.44)
in center handle position
Weight (lb/kg) 187 (84.82)
Engine Specifications
Engine Generac G-Force
Fuel Tank Capacity 1.72 gal (6.5 L)
Oil Capacity 37 oz (1.1 L)
Oil Type See chart in Adding Oil.
Spark Plug TORCH F6RTC or equivalent
Spark Plug Gap .028-.032 in (0.7-0.8 mm)

6Owner’s Manual for Stump Grinder
General Information and Setup
Remove Contents from Carton
1. See Figure 2-2, Figure 2-3, Figure 2-4, and Figure 2-
5. Remove and verify carton contents prior to assem-
bly. Carton contents should contain the following:
Figure 2-2. Hardware Supplied in Product Package
Figure 2-3. Maintenance Meter
Figure 2-4. Manual Caddy
Figure 2-5. Tow Hitch Kit
Item Description QTY
A Bolt, HHCS, 5/16-18 x 1-1/4", GR5, ZP 1
B Nut, Nylon Lock, 5/16-18 1
C Bolt, HHCS, 3/8-16 x 1-1/4", GR5 3
D Bolt, HCS, 3/8-16 x 2-1/4", Full Thread 1
E Washers, Flat, 5/16", USS 8
F Nut, Nylon Lock, 3/8-16 4
G Nut, Nylon Lock, 3/8-16, Low Profile 1
H Brake, Band 1
I Cable Tie, 7-1/2" 8
JCable,Brake 1
K Barrel, Cable 1
Item Description QTY
A Wire, 66 in 1
B Meter 1
C Panel Adapter 1
DCableTies 3
006017
A
D
FE
C
B
J
K
G
I
H
008072
D
C
B
A
Item Description QTY
A Manual Caddy 1
B Clamp, Cable 2
C Nut, Nylon Lock 5/16”-18 LP 2
D Bolt, HCS, 5/16”-18X3, GR5, ZP 2
Item Description QTY
A Tow Bar, w/Labels 1
B Adapter, Tow Bar 1
C Nut, Nylon Lock, 3/8-16, ZP 5
D Bolt, HCS, 3/8-16 x 1 1/4", GR5 4
E Bolt, HCS, 3/8-16 X 3.5", GR5, ZP 1
F Pin, Linch, 3/8" x 2.5", w/wire lock 1
G Pin, Hairpin Cotter, .12" Dia. 2-3/8" 1
H Pin, Clevis, .375" x 2.00" 1
I Nut, Nylon Lock, 1/2-13 2
J Bolt, 1/2-13 X 3.00", GR5, ZP 2
K Adapter, Hitch 1
L Washer, Flat 3/8 SAE 10
M Hitch, Trailer 1
008070
A
C
BD
008070
A
B
C
D
E
I
L
H
F G
J
K
M

Owner’s Manual for Stump Grinder 7
General Information and Setup
2. Contact Generac Customer Service at 1-888-436-
3722 (1-888-GENERAC), or www.generac.com
with the unit model and serial number for any miss-
ing carton contents.
3. Record model, serial number, and date of pur-
chase on front cover of this manual.
Assembly Instructions
1. See Figure 2-6. Loosen right wheel bolt (A) using
a 1/2” wrench with the wheel on the ground.
Figure 2-6. Wheel Bolt
2. Use a suitable lifting device and raise the machine
to allow for wheel removal.
3. Remove the bolt, lock washer, large flat washer
and right side wheel from the axle.
NOTE: Each wheel contains two bushings. Note how the
bushings are installed for reassembly.
4. See Figure 2-7. Position the right side of the han-
dlebar (C) with the lower mounting hole aligned
with the center hole (D) in the frame.
Figure 2-7. Mounting Configuration
5. Loosely install a 3/8-16 x 1-1/4" bolt, washer and
locknut into the lower handlebar hole.
6. Rotate the handlebar up and loosely install a
3/8-16 x 1-1/4" bolt, washer and locknut.
7. Replace the right side wheel, including the two
bushings, and secure with the bolt, washer and
locknut by hand.
8. Lower the machine to the ground and finish tight-
ening the right wheel bolt with a 1/2" wrench.
9. Loosen the left wheel bolt using a 1/2" wrench.
10. Use a suitable lifting device and raise the machine
to allow left wheel removal.
11. Remove the bolt, lock washer, large flat washer
and left wheel.
12. See Figure 2-8. Align the left side of the handlebar
(F) with the holes in the frame. At the top hole,
pass a 3/8-16 x 2-1/4" bolt with washer through the
frame from the inside and through the handle bar
and install a locknut with washer against the han-
dlebar (G). Tighten with two 9/16" wrenches.
Figure 2-8. Handlebar Installation
13. At the bottom hole, pass a 3/8-16 x 1-1/4" bolt with
washer through the hole in the handle bar and into
the frame and install a locknut with washer (H).
Secure with two 9/16" wrenches.
14. Tighten the right side handlebar hardware using
two 9/16" wrenches.
15. See Figure 2-9. Place the brake band (I) over the
brake drum (J) with the top loop of the band over
the 2-1/4" bolts.
Figure 2-9. Brake Band
16. Install the low profile 3/8" lock nut (J) against the
brake band with a 9/16" wrench.
NOTE: The brake band should be able to rotate with no
side to side movement.
006018
A
006018
C
D
006022
G
F
H
006023
J
I
K

8Owner’s Manual for Stump Grinder
General Information and Setup
17. See Figure 2-10. Slip the barrel end of the brake
cable into brake lever socket (L) then insert brake
cable sheath (M) into the end of brake lever
bracket (N).
Figure 2-10. Installing Brake Cable
18. See Figure 2-11. Turn the top jam nut (O) up the
brake cable threads.
Figure 2-11. Installing Brake Cable to Brake Drum
19. Turn the bottom jam nut (P) down and off the
threaded portion of the cable.
20. Insert the threaded portion of the cable down
through the hole in the bracket (Q).
21. See Figure 2-12. Attach the brake cable spring (R)
to the bottom loop of the brake band using a 5/16-
18 x 1-1/4" bolt and locknut (S). Tighten with two
1/2" wrenches.
Figure 2-12. Installing Brake Cable Spring
22. See Figure 2-13 . Pull up on brake cable (T) until
resistance is felt and brake band touches brake drum.
Figure 2-13. Tightening the Jam Nuts
23. Turn the top jam nut (U) down against the bracket.
24. Turn the lower nut (V) up against the bracket
25. Tighten both nuts against the bracket using two
1/2" Wrenches.
26. See Figure 2-14. Place key (W) into the axle key-
way if removed earlier.
27. Align the key slot in the wheel with the key and
slide the wheel onto the axle.
Figure 2-14. Installing Wheel
28. Install the wheel bolt, locknut and flat washer
using a 1/2" wrench.
29. Lower the machine to the ground and finish tight-
ening the right wheel bolt with a 1/2" wrench.
30. See Figure 2-15 . Cut the cable tie securing the wire
harness at the rear of the unit using wire cutters
.
Figure 2-15. Cable Tie
006024
L
M
N
006025
P
Q
O
006026
R
S
006027
U
T
V
006028
W
006029

Owner’s Manual for Stump Grinder 9
General Information and Setup
31. See Figure 2-16. Plug the key switch connectors
to either key switch terminal (X).
Figure 2-16. Key Switch Connector
32. Plug the black operator presence connector into
the harness connector (Y).
33. See Figure 2-17. Move the cable tie (Z) securing
the throttle cable to the right side handlebar up to
the top portion of the handlebar.
Figure 2-17. Throttle Cable Tie
NOTE: The air filter cover and air filter may need to be
removed to allow access to the throttle linkage for the fol-
lowing steps.
34. See Figure 2-18. Loosen the Bowden clamp (A)
with a Phillips screw driver or 5/16" wrench and
position the cable sheath (B) under the clamp.
Figure 2-18. Throttle Linkage
35. Hook the “Z” bend end of the throttle cable in the
first hole in the throttle linkage (C).
36. See Figure 2-19. Tighten cable by holding engine
throttle lever (D) in the IDLE position while pulling
on cable sheath.
Figure 2-19. Engine Throttle Level
37. While still holding the sheath in position, release
the engine throttle lever.
38. Tighten the bowden clamp onto the sheathing with
a Phillips head screwdriver. Do not over-tighten.
39. Actuate throttle lever to verify throttle linkage trav-
els smoothly to full throttle and back to IDLE
40. See Figure 2-20. Use cable ties to secure cables
and wires to the control panel and handlebars (E).
Figure 2-20. Cable Tie Locations
X
Y006030
006031
Z
006032
A
B
C
006033
D
006034
E

10 Owner’s Manual for Stump Grinder
General Information and Setup
Maintenance Meter Installation
1. Gently pry the black factory panel Insert from the
control panel
2. Insert the panel adapter from the kit into the open
hole in the control panel. Verify the adapter flange
has engaged the panel completely.
3. See Figure 2-21. Insert the meter firmly into the
panel adapter until it snaps into place. The meter
flange should be flat against the face of the
adapter.
Figure 2-21. Maintenance Meter Installation
4. Slide the sensor wire onto the sensor wire connec-
tor on the back of the meter.
5. Run the sensor wire from the meter to the handle-
bar and secure the wire to the handlebar with two
cable ties.
6. Route the balance of the sensor wire forward fol-
lowing the existing wiring harness toward the
engine spark plug wire. Trim the excess material
from the cable tie.
7. See Figure 2-22. At a convenient point along the
spark plug wire wrap four or five turns of meter wire
(A) tightly around the spark plug wire (B) and
secure it to itself with a cable tie (C). Cut and dis-
card the balance of the wire.
Figure 2-22. Maintenance Meter Installation
NOTE: Avoid placing the wire on, or near hot surfaces.
Attaching Manual Caddy
All product documents should be stored in the manual
caddy.
1. See Figure 2-23. Attach caddy clamps (A) to right
handlebar.
2. Align top and bottom caddy mounting hole with
holes in clamps, and secure caddy to clamps with
two 5/16”-18X3 bolts with 5/16” washers and 5/16”
locknuts (B).
Figure 2-23. Manual Caddy
Installing Tow Hitch Kit
Installing Tow Bar Adapter
1. See Figure 2-24. Align holes in tow bar adapter
with holes in frame.
2. Secure the flat section of bar adapter to the frame
with two 3/8-16 x 1 1/4” bolts with 3/8” washer and
two 3/8” locknuts with 3/8 washers (B) using two
9/16" wrenches.
3. Secure the square tube section of the tow bar
adapter with a 3/8-16 X 3.5" bolt with 3/8” washer
and a 3/8” locknut with 3/8” washer (C) using two
9/16" wrenches.
Figure 2-24. Installing Tow Bar Adapter
008073
A
C
BA
008071
A
B
008343
A
B
C

Owner’s Manual for Stump Grinder 11
General Information and Setup
Assembling Hitch Adapter
1. See Figure 2-25. Secure hitch adapter (A) to tow
bar (B) with two 3/8-16 x 1-1/4" bolts with 3/8”
washers and two 3/8” locknuts with 3/8” washers
(C) using two 9/16" wrenches.
Figure 2-25. Assembling Hitch Adapter
Assembling Trailer Hitch
1. See Figure 2-26. Secure trailer hitch (A) to tow bar
(B) with two 1/2-13 X 3" bolts and two 1/2” locknuts
using two 3/4" wrenches.
Figure 2-26. Assembling Trailer Hitch
Adding Oil
IMPORTANT NOTE: The unit is shipped without oil in
the engine. Oil must be added prior to operation.
1. Move machine to a level surface and place blocks
under the front of the machine to level the engine.
NOTE: The frame and engine must be level to ensure an
accurate oil reading.
2. See Figure 2-27. Remove oil dipstick/fill cap (A)
and wipe dipstick clean.
Figure 2-27. Oil Dipstick
3. Add 16 oz (473 mL) of engine oil. Climate deter-
mines proper engine oil viscosity. See Table 1:
Engine Oil Requirements to select correct viscos-
ity. SAE 10W-30 is recommended for general use.
NOTE: Use 4-stroke engine oil, API service classification
SJ class or equivalent.
Table 1 – Engine Oil Requirements
4. Wait one minute for oil to settle.
5. See Figure 2-28. Reinsert dipstick into oil filling
hole without screwing it in. Pull the dipstick out,
and verify oil level is in crosshatched section (A).
Figure 2-28. Oil Range
6. If the oil level is low, add a few ounces of oil at a
time, rechecking the dipstick until the oil reaches
the full mark. Do not overfill.
008344
B
C
A
008345
B
C
A
(000135)
CAUTION
Engine damage. Verify proper type and quantity of
engine oil prior to starting engine. Failure to do so
could result in engine damage.
(000210)
WARNING
Skin irritation. Avoid prolonged or repeated contact with
used motor oil. Used motor oil has been shown to cause
skin cancer in laboratory animals. Thoroughly wash
exposed areas with soap and water.
006035
A
006809
SAE 30
5W-30/10W-30
15W-40
A
000116
WARNING
Personal injury. Remove leveling device before
operating the unit. Failure to do so could result in
serious injury or equipment damage.
(000471)

12 Owner’s Manual for Stump Grinder
General Information and Setup
Adding Fuel
NOTE: Never use contaminated gasoline or mixed gaso-
line with oil. Never allow dust, foreign matter or water to
enter fuel tank.
1. Place unit on a firm, level surface in a well venti-
lated area.
2. Verify unit is OFF and cooled for a minimum of two
minutes.
3. See Figure 2-29. Remove the gas fill cap (B).
Figure 2-29. Fuel Cap
4. Fill tank with fresh, unleaded gas (with a minimum
85 octane rating) to 0.25 in (6.4 mm) from the bot-
tom of the fill neck to allow for fuel expansion.
5. Install fuel fill cap.
NOTE: Allow spilled fuel to evaporate before starting
unit.
Connecting Battery Cable
All units are shipped with the negative terminal battery
cable disconnected. Before using the unit, connect the
battery cable.
1. See Figure 2-30. Connect the negative (A) cable
to the negative (-) terminal on the battery (B).
Figure 2-30. Connecting Battery Cable
Checking Tire Pressure
1. See Figure 2-31. Remove the valve stem protec-
tive cap (A) and check the tire pressure with a tire
pressure gauge.
Figure 2-31. Valve Stem
2. Compare the tire pressure reading with the manu-
facturer's recommended tire pressure stamped on
the side of the tire.
3. If the pressure is too low, add air through the valve
stem with an air hose.
4. Replace the valve stem protective cap.
(000105)
DANGER
Explosion and Fire. Fuel and vapors are
extremely flammable and explosive. Add fuel
in a well ventilated area. Keep fire and spark
away. Failure to do so will result in death
or serious injury.
(000214)
DANGER
Explosion and Fire. Do not fill fuel tank past full line.
Allow for fuel expansion. Overfilling may cause fuel
to spill onto engine causing fire or explosion, which
will result in death or serious injury.
WARNING
Explosion and Fire. Do not smoke while
refueling unit. Failure to do so could result in
death, serious injury, or property or equipment
damage. (000284a)
006485
B
006039
B
A
WARNING
(000462)
Personal injury. Inflate tires to manufacturer’s recom-
mended pressure indicated on tire. Failure to do so
could result in death, serious injury, and equipment
damage.
006038
A

Owner’s Manual for Stump Grinder 13
General Information and Setup
Hitching Unit to Tow Vehicle
Hitch Adapter
1. See Figure 2-32. Slide tow into tow bar adapter,
align holes, and secure with linchpin (A).
Figure 2-32. Installing Tow Bar to Stump Grinder
2. See Figure 2-33. Position hitch adapter (B) on tow
vehicle with tow vehicle hitch plate (C) between
hitch adapter and tow bar (D).
3. Secure hitch adapter to tow vehicle with clevis pin
and hairpin cotter pin (E).
Figure 2-33. Hitch Adapter
Trailer Hitch
1. See Figure 2-34. Slide tow bar into tow bar
adapter, align holes, and secure with linchpin (A).
Figure 2-34. Installing Tow Bar to Stump Grinder
1. See Figure 2-35. Lift latch assembly (B) and place
the tow hitch assembly onto the ball.
2. Close the latch assembly to lock tow hitch assem-
bly onto tow ball.
3. Verify hitch coupler (C) is properly and securely
attached to tow ball.
Figure 2-35. Trailer Hitch
4. See Figure 2-36. Insert locking pin (E) into the
hole in the latch assembly to lock the assembly in
the closed position.
Figure 2-36. Locking Pin
WARNING
Personal injury. Never tow on roads. Towing on roads
could result in death, serious injury, unit, or property
damage.
(000504)
Personal Injury. Remove tow bar from stump grinder
before grinding stumps. Grinding stumps with tow
bar installed could result in death, serious injury, or
damage to property or the unit.
(000581)
WARNING
Loss of control. Do no drive over 5 mph (8 km/h) on
flat terrain or over 4 mph (6 km/h) on rough terrain.
Doing so could resulting in loss of control of the
equipment and serious injury. (000455)
WARNING
008346
A
008347
B
DC
E
008346
A
008347
B
D
C
E
B
C
008348
008349
B
D
C
E
B
C
E

14 Owner’s Manual for Stump Grinder
General Information and Setup
High Altitude Replacement Kit
At high altitude, a standard carburetor air-fuel mixture will
be too rich. A rich mixture decreases performance,
increases fuel consumption, fouls the spark plug and
causes hard starting. Operation at high altitude, for
extended periods of time, may increase emissions.
Proper operation at higher altitudes can be improved by
installing an altitude kit when required. See Table 2:
High Altitude Replacement Kit to determine when an
altitude kit is required.
Table 2 – High Altitude Replacement Kit
At elevations above 8000 feet, the engine may experi-
ence decreased performance even with a high altitude kit
Kits can be obtained by contacting Generac Customer
Service at 1-888-436-3722 (1-888-GENERAC), or
www.generac.com. Kits must be installed by a qualified
individual.
NOTE: If a
carburetor is replaced, the proper high altitude kit
jet will
need to be installed into the replacement carburetor.
NOTE: The warranty may be void if necessary
installation of a high altitude kit is not made for high alti-
tude use.
Altitude Range Part Number
0-3000 ft Not required
3000-8000 ft 100000359431

Owner’s Manual for Stump Grinder 15
Operation
Section 3: Operation
Operation and Use Questions
Contact Generac Customer Service at 1-888-436-3722
(1-888-GENERAC), or www.generac.com with
questions or concerns about unit operation and
maintenance.
Controls and Symbols
See Figure 3-1. The throttle control lever and choke con-
trol uses icons to represent settings. Be familiar with icon
meanings prior to unit operation.
Figure 3-1. Control Symbols
Starting Engine
IMPORTANT NOTE: Oil must be added before start-
ing the engine for the first time. Units are shipped
without oil. Do not overfill.
NOTE: The operator presence lever must be held down
for the engine to start and continue running. If the
machine needs to be stopped quickly for any reason,
release the operator presence lever.
Manual Starting
1. See Figure 3-2. Verify the fuel shut-off (A) is in the
open position.
2. Move the choke control lever (B) to the CLOSED
position. If the engine is warm leave the choke con-
trol lever in the OPEN position.
Figure 3-2. Fuel Shut-Off and Choke Control Lever
3. See Figure 3-3. While holding down operator pres-
ence lever (C), slowly pull the recoil starter handle
until resistance is felt. Let the cord retract slightly
and then pull the cord rapidly to start the engine.
Figure 3-3. Operator Presence Lever and Recoil
(000100a)
WARNING
Consult Manual. Read and understand manual
completely before using product. Failure to
completely understand manual and product
could result in death or serious injury.
WARNING
(000466)
Personal injury. Never operate unit on slippery, wet,
muddy, or icy surfaces. Doing so could result in death,
serious injury, equipment or property damage.
WARNING
(000467)
Personal injury. Always verify all guards and shields are in
place prior to use. Removal or modification of guards and
shields could result in serious injury or equipment damage.
WARNING
Personal injury. Before performing service, turn unit OFF,
release throttle and operator presence levers, remove spark
plug wire and secure away from plug. Failure to do so could
result in death or serious injury. (000468)
WARNING
(000469)
Personal injury. Allow only one person to operate the unit at
any time. Failure to do so could result in death, serious injury
or equipment damage.
WARNING
(000460)
Personal injury. Use caution when operating unit over
uneven terrain or slopes. Failure to do so could result
in death, serious injury, equipment or property
damage.
RUN IDLE
CLOSED OPEN
WARNING
(000507)
Personal injury. Do not modify the operator presence
lever in any way. Doing so could result in death
or serious injury.
006040
B
A
005812
C
D

16 Owner’s Manual for Stump Grinder
Operation
4. As the engine warms up, slowly adjust the choke
toward the OPEN position. Wait until the engine
runs smoothly before each choke adjustment.
5. When the engine is warmed up and running
smoothly, move the choke to the OPEN position.
Electric Starting
1. See Figure 3-4. Verify the fuel shut-off (A) is in the
OPEN position.
2. Move the choke control lever (B) to the CLOSED
choke position. If the engine is warm leave the
choke control lever in the OPEN position.
Figure 3-4. Fuel Shut-Off and Choke Control Lever
3. See Figure 3-5. Hold down the operator presence
lever (C) and turn the key switch (D) fully to the
start position until the engine starts. The key will
move back to the center position when released.
Figure 3-5. Operator Presence Lever and Key
4. As the engine warms up, slowly adjust the choke to
the OPEN position. Wait until the engine runs
smoothly before each choke adjustment.
5. When the engine is warmed up and running
smoothly, verify the choke is fully in the OPEN
position.
Stopping Engine
1. Move the throttle control lever to the IDLE position.
2. Release the operator presence lever.
3. After the engine has stopped, remove the key for
safety.
Grinding the Stump
NOTE: If the engine ever bogs down during cutting, lift
the cutting head from the stump and allow the cutting
head to return to speed before further cutting.
1. See Starting Engine. Start the engine and allow it
to warm up at idle for a few minutes.
2. See Figure 3-6. Move the unit into position with the
cutter head to the right of the stump (A). The cutter
head should be near the top edge of the stump but
not touching.
Figure 3-6. Starting Position
006040
B
A
005812
C
D
WARNING
Personal injury. Verify work area is free of electrical
cables, barbed wire, and other foreign objects before
operating the unit. Failure to do so could result in
death, serious injury, unit, or property damage.(000523)
WARNING
Personal injury. Cut stump as close to ground as
possible before grinding. Failure to do so could result
in death, serious injury, unit, or property damage.
(000521)
WARNING
(000410)
Projectile risk. Remove all debris from work area
before operating unit. Failure to do so could result in
death, serious injury, or property or equipment
damage.
006042
A