DOSKO 337S-13HC User manual

1
Owner’s Manual
Instructions for Operation, Maintenance
Stump and Root Grinder
337-13HC, 357-13HE, 337S-13HC
620-20HE, 620-25KE
Your Dosko grinder is intended for outdoor-use only and can be used to remove many tree stumps and
exposed root systems close to ground level. By moving the blade in sweeping movements laterally over
the top and front of the stump, you can gradually grind it away. Make sure you completely read and
understand this manual before using the grinder for the first time.
WARNING
READ and UNDERSTAND this manual completely before using the grinder! Failure to properly operate,
and maintain this grinder could result in serious injury or death to the operator or bystanders.
All machines have hazards associated with their operation. This stump grinder has certain special hazards,
which you must be aware of. As an operator or owner you have a duty to be aware of these hazards and know
preventive measures to take to avoid them. When reading this manual pay particular attention to avoiding these
hazards.
In particular, be aware of the following:
Know location of buried electrical and other utility lines.
Do not allow children or untrained adults to operate.
Wear eye protection and other personal protection against flying rocks and debris.
Check that cutter wheel teeth are secured, sharp and not missing.
Do not operate if operator presence bar fails to stop engine upon release.
Make sure no children or bystanders are within 75 feet of stump grinding operation.
Protect cars, windows and other objects within 75 feet from flying debris.
Be prepared for machine “kickback” when initially contacting the stump.
Be aware of potential for carbon monoxide (CO) poisoning.
Prevent fires/explosions from fueling.
Do not attempt to perform adjustments, declog or clean unit while engine is running.
Avoid burns from engine or hot exhaust.
Avoid using in wet or icy conditions where falls may occur.
Details about these hazards are found throughout the manual and are summarized at the end of the manual under
“Important Safety Information.”
STOP!
ADD ENGINE OIL, FUEL & BATTERY:Your stump grinder comes fully assembled and requires only that you add
engine oil to crankcase, fuel to tank, and a battery.
INSPECT COMPONENTS:Closely inspect to make sure no components are missing or damaged. See the “Receiving
Your Unit” section for instructions on whom to contact to report missing or damaged parts.
Any Questions, Comments, Problems, or Parts Orders
Call your dealer or Dosko Customer Service 1-866-298-3659
MODEL NUMBER: 337-13HC, 357-
13HE, 337S-13HC
620-20HE, 620-25KE
SERIAL NUMBER: _____________
M2961000V.1

Hazard Signal Word Definitions
2

Table of Contents
3
Part I. Introduction
About Your Grinder ..............................................................................................................4
Safety Decal Locations............................................................................................................5
Safety Decals............................................................................................................................6
Transporting & Receiving:
1. Receiving Your Unit......................................................................................................7
2. Towing Instructions.......................................................................................................7
Machine Component Identification ......................................................................................8
Part II. Operation
Operation:
1. Pre-Start Check List & Procedures...............................................................................9
2. Starting the Grinder.......................................................................................................12
3. Stopping Engine............................................................................................................13
4. Grinding Stump.............................................................................................................14
5. Refueling.......................................................................................................................15
6. Storing Machine............................................................................................................16
Part III. Maintenance and Repair
Maintenance (To be done by owner or Rental Dealer) ..........................................................19
1. Belt Tension Adjustment ............................................................................................ 21
2. Stop-Switch Adjustment............................................................................................. 22
3. Setting Teeth............................................................................................................... 22
4. Schedule...................................................................................................................... 24
Specifications..........................................................................................................................25
Part IV: Important Safety Information
Summary of Important Safety Information for Operation .............................................. 26
Special Safety Information on Static Electricity................................................................ 29
Parts Explosion........................................................................................................................ 30
Wiring Diagrams..................................................................................................................... 32
Assembly Instructions ........................................................................................................... 35
Warranty.................................................................................................................................... 39
California Proposition 65 Information............................................................................ 40

About Your Grinder
4
Thank you for purchasing or renting your Dosko grinder!
Owner/Operator/Renter Training
Read and follow all instructions and safety precautions presented throughout this manual. A summary of
important safety information can be found at the end of the manual. Keep this manual for reference and
review. If the owner of this unit is different than the operator, give a copy of this manual to any
operator to read.
Rental Companies
All persons to whom you rent/loan this grinder must have access to this manual and read it. Check the
tube on the side of the unit to make sure a manual is inside. Advise all persons who will operate the
machine to read it. You should also provide personal instruction on how to safely operate the grinder and
remain available to answer any questions a renter/borrower might have. If videos are available, have
renter watch training video.
Engine Instructions
For detailed Engine operation and maintenance information, always refer to the engine Owner’s Manual
furnished with the grinder.
Product Suitability
Before using, the user shall determine the suitability of this product for this intended use and assumes
liability therein.
Your Dosko grinder can be used to remove many tree stumps and exposed root systems close to ground
level. By moving the blade in sweeping movements laterally over the top and front of the stump, you can
gradually grind it away. Make sure you completely read and understand this manual before using the
grinder for the first time. If you have any questions, contact your retail or rental dealer or Dosko
Customer Service at 1-866-298-3659.
WARNING: Never attempt to cut on a slope exceeding 15.
Exercise caution when cutting stumps on an incline, as the machine may shift or slide unpredictably. Never
attempt to cut with the machine uphill or downhill from you as it may slide toward you or you may fall
toward the machine. Cut only on a slope from the side.
˙
Dosko is constantly improving its products. The specifications outlined herein are subject to change
without prior notice or obligation. The purchaser and/or user shall assume liability for any modification
and/or alterations of this equipment from original design and manufacture.
Contact Dosko Customer Service at 1-866-298-3659 for any questions about the appropriate use of
this grinder or about optional accessories.
Warranty Registration
Please fill out and submit the warranty registration card so that we have your contact information for any
future product literature or replacement parts you may need.

Safety Decal Locations
5
Reference #
Part #
Description
Model #
1
784272 decal kit
Flying Debris Hazard (person)
All
2
784291
Flying Debris Hazard (direction)
- located on base OR battery box top
All
3
784079
Tow Position
All
4
784272 decal kit
Amputation and Entanglement Hazard
All
5
799546
California Proposition 65 Warning
All
6
784272 decal kit
Poisonous Gas Hazard
All
7
783540
784298
784299
Control Panel
337-13HC, 337S-13HC
620-20HE
357-13HE, 620-25KE
8
784272 decal kit
Personal Injury / Fire, Explosion / Entanglement
Hazards
All
9
786635
Burn Hazard
- located on belt guard OR engine
All
10
799952
Spark-Strike Warning
337-13HC, 337S-13HC
620-20HE
WARNING
ALWAYS make sure safety labels are in place and in good condition. If a safety label is
missing or not legible, order new labels.

Safety Decals
6
To order replacement safety labels, call Dosko Customer Service at 1-866-298-3659.
All grinder units can be transported via trailers or with the purchase of an optional towing kit
package can be towed behind the vehicle.
2
1
3
5
6
7
8
4
9
10

Transporting and Receiving
7
1. Receiving Your Unit
For all Units
You should inspect the grinder immediately after you receive delivery.
See the “Machine Component Identification” section of this
manual for a diagram of the grinder and its components.
If you have missing components, contact your rental company or Dosko
Customer Service at 1-866-298-3659.
New Unit: Truck
Delivery
Depending on your unit and model, it may have been shipped on a wooden skid,
cardboard container or other appropriate method.
For any shipping damage, make sure the delivery driver acknowledges it and a
claim is filed with the freight delivery company.
Note: Shipping damage claims are not covered by Dosko
warranty. Please contact carrier!
If any assembly is required. Separate assembly instructions will be included.
New Unit: From a
Dealer
Your unit may be completely assembled and ready to run depending on the
dealer. If not, please refer to “factory delivery” below. Read the “Operation:
Preparing for Operation” section (page 9), and verify that the unit has been properly
“prepped” before initial use.
Factory Delivery
In these cases, your unit has been tested and pre-run but will require additional
assembly. See “Assembly Instructions” section at the end of the manual.
2. Towing Instructions
On Towable
Models
Optional towing
packages:
Part # 296108
(337-13HC &
357-13HE)
Part # 296107
(620-20HE &
620-25KE)
Each state has legal requirements for towing equipment and trailers (such as lighting
and licensing). Be sure receiver on towing vehicle is bolted tightly. Towing vehicle
capability must be matched to trailer weight and type of hitch arrangement.
1. Review towing safety instructions in
your vehicle manual.
2. Attach grinder to vehicle hitch using
only a 2” ball.
3. Be sure the tow bar is bolted tightly to
the towing vehicle receiver.
4. Position tow bar into socket, then
insert lock pin with safety clip.
5. Be sure that the stump grinder safety
chains are hooked, closed and locked to
the towing vehicle by using the
coupling links.
6. Make sure the grinder wheel lug nuts
are fastened tightly, tires are fully
inflated and in good repair.
WARNING:
Do not tow over 45 mph unless a higher speed rated trailer is being used.

Machine Component Identification
8
Reference #
Description
1
Control Panel
2
Pin Adjustment Handle Bar
3
Tire and Hub
4
Discharge Flap
5
Belt Guard
6
Tooth Pocket
7
Cutting Tooth
8
Cutter Wheel Disc
9
Cutter Guard
10
Gas Tank
11
Engine
12
Adjustable Brake Lever
13
Handle Bar
14
Operator Presence Handle Bar

Operation
9
1. Pre-start Check List & Procedures
CAUTION:
Add engine crankcase oil. A new engine is shipped without oil. You must add the correct
amount of oil to engine crankcase or engine will be damaged beyond repair.
Before starting the engine you will want to make sure you have completed the following:
1. Marking Underground Utilities
2. Checking Controls
3. Checking/Adding Oil
4. Filling Stump Grinder Gasoline Tank
5. Inspecting Fuel System for Leaks
6. Adjusting Handle Bar
7. Wearing Personal Protection
8. Trimming Stump with Saw
9. Clearing Area of People and Objects
10. Working During Daylight
11. Battery Installation
Each of these procedures is discussed in detail below.
Marking
Underground
Utilities
Call 811 or your local utility company to request marking utilities 3
days before stump grinding. Trees can grow on top of and around
underground wiring that was installed many years before a tree was
planted.
Check Controls.
Check that:
All guards are in place and tight
Operator presence bar switch is free moving.
Inspect tires and rims for looseness, damage, and tire inflation.
Check Cutting
Teeth
Inspect cutting teeth for tightness and sharpness. Only use factory-approved
parts for repair.
Check/Add Oil
Check the oil level using the dipstick and add oil as needed daily.
Using a funnel, add oil up to the FULL mark on the dipstick with the
recommended oil type for your engine and expected ambient conditions.
(See engine Owner’s Manual for oil type and capacity, and more detailed oil
check/fill instructions.)
WARNING: Burn hazard
Never open oil fill port while engine is running. Hot oil can spray
over face and body.
˙

Operation (cont’d)
10
Fill Stump Grinder
Gasoline Tank
Check the gasoline level in the grinder’s fuel tank. If needed, fill tank with
fresh unleaded gasoline from a portable container, after first reading the
warnings and instructions below.
- Do NOT fill the gas tank to the top. Gasoline may spill when operating
on a slope.
- Do NOT overfill the gasoline tank. Allow at least 1” of empty space
below the fill neck to allow for fuel expansion.
WARNING:Gasoline fire/explosion hazard
Gasoline is highly flammable and explosive. Heat, sparks, and
flames can ignite gasoline vapors, which can become widespread
during fueling. A flash fire ignition and/or explosion could result
and cause serious injury or death. The following conditions could
result in gasoline ignition/explosion:
gas vapor collection inside enclosures
static electric sparks
sparks from electric wiring, batteries, or running engines
sources of heat (such as a hot engine or exhaust)
open flames, including pilot lights
Inspect Fuel
System / Check for
Leaks
Inspect fuel system & check for leaks BEFORE starting grinder.
WARNING: Fuel leak hazard
A leaking fuel line no matter how small can be the source of a fire or
explosion when starting or operating the engine.
Inspect the entire fuel system. Look for: Signs of leaks or deterioration,
chafed or spongy fuel hose, loose connections, loose or missing fuel
hose clamps, damaged gasoline tank, or defective gasoline shut-off
valve.
If grinder is in an enclosed area and you smell gas, DO NOT start
engine! DO NOT light a match. DO NOT flip on an electrical
switch. Exit area immediately leaving doors open and call fire
department.
Adjust Handle Bar
Handle bar may have to be adjusted to accommodate for the height of stump
or desired depth. When grinding above or below ground level, adjust handle
bar for better control and comfort. Note: Your stump grinder should not be
used more than 10 inches maximum below ground
Personal Protection
Use approved protective clothing and approved protective equipment
when using the machine.
1) Always wear ANSI-approved and OSHA-compliant safety glasses
with side shields and a full-face shield.
2) The use of ear plugs or other hearing protection device is also
recommended for persons working within 15-20 feet of the running
grinder for longer than a few minutes. Hearing can be damaged from
prolonged, close-range exposure to the type of noise produced by this
grinder.

Operation (cont’d)
11
3) Wear long pants to protect legs from sparks, hot engine and flying
debris.
4) Never wear jewelry or loose-fitting clothing when starting or
operating the grinder or any mechanical device. Loose or dangling
apparel, jewelry or hair can become entangled in moving parts.
Trim Stump with
Saw
Cut or trim the stump preferably to ground level using a power saw.
Clear Area
Dig away the earth and remove any stones near the tree stump or roots that
may interfere with your work.
Work During
Daylight Hours
Only use the machine in daylight or in well-lit conditions. Never operate
the grinder after dark.
Battery Installation
Your stump grinder’s engine is equipped with an electric starter (depending on model), which
requires the installation of a 12-volt lawn tractor size battery (Group U1). See the Engine owner’s
manual for battery rating.
The battery is to be supplied by the customer and should be installed in the protective battery box
located near the engine. (The inside dimensions of the battery box are 9” L x 6” W x 8-1/2” H). A
battery hold-down strap has been supplied along with (2) 5/16 x 3/4” bolts and (2) 5/16” nuts in
order to secure the battery inside the battery box. Follow the instructions detailed below for
connecting and disconnecting the battery.
WARNING: Battery hazards
Batteries are hazardous because they contain caustic acid, can emit explosive gases, and can cause
electric shock. Caution must be exercised when making connections to a battery to avoid shock and
contact with the acid, and to prevent any sparking that could lead to an explosion.
ALWAYS follow the general battery safety rules and instructions listed below.
General Battery
Safety Rules
ALWAYS use eye protection when handling batteries.
NEVER smoke or work near sparks or other sources of ignition.
NEVER touch both battery terminals at the same time with your hand or
any non-insulated tools.
If battery acid contacts skin or clothing, flush immediately with water and
neutralize with baking soda.
Connecting the
battery
Always connect the cables in the following sequence to avoid possible shock:
1. Find the battery cables located inside the battery box.
2. Connect the red cable to the positive (+) terminal of the battery.
3. Then connect the black cable to the negative (-) terminal of the battery.
Disconnecting the
battery
Always disconnect cables in the following sequence to avoid possible shock.
1. First, disconnect the black cable from the negative (-) terminal of the
battery.
2. Next, disconnect the red cable from the positive (+) terminal of the
battery.

Operation (cont’d)
12
2. Starting the Grinder
After you have completed the pre-start checklist and procedures, you are ready to start the
grinder.
The following directions detail how to start the engine of your grinder.
WARNING:
Never attempt to use the grinder without proper protective equipment,
particularly eye protection and a full-face shield.
To start the grinder:
Note: For additional engine starting instructions see your Honda/Kohler engine manual.
1) Before starting you should raise or lower the handle bar to a comfortable position to
accommodate the height of the stump you will be grinding.
2) Place stump machine into position with cutting blade near the front-top edge of the stump.
3) Using lever on handle to lock the one wheel brake.
Note: For tighter brake adjustment, turn knob on top of brake lever.
WARNING:
Stay in the OPERATOR POSITION while actuating controls. Never leave grinder unattended.
4) Pull Engine Switch ON. (Some models may have an additional on/off switch located on the
engine)
5) Pull choke if engine is cold. If engine is hot, do not use choke.
6) Grip operator presence bar & grinder handle bar together in left hand.
WARNING:
A rotating cutting blade is very dangerous. Stay at the controls and keep
others away until you are sure the blade has come to a complete stop.
WARNING:
Cutting wheel immediately begins rotating when starter is pulled. There
is no clutch or gear to separately start or stop cutter wheel.
7) Since the cutter wheel starts rotating when starter is activated, press down on handle bar to
lift cutter wheel off the ground.
8) A) Pull Start: Rapidly pull “Start” cord (recoil starter) with right hand several times until
engine starts. Allow starter cord to return slowly.
B) Electric Start: Turn Key switch to the START position and hold until the engine starts.
9) If engine does not start, repeat steps 5-8.

Operation (cont’d)
13
3. Stopping the Engine
Stop the engine using the following steps:
1. While holding blade off ground, release the
operator presence bar. Wait until the blade
completely stops. Lower the blade so it is resting
against the ground.
2. Make sure brake is set before leaving the controls,
particularly if you are on an incline.
3. Turn engine switch to OFF position.
4. Allow the engine to cool for at least 5 minutes
before releasing brake and moving to storage or
transporting. A hot engine can be a fire hazard.
Operator
presence bar
Handle bar
adjustment
Cutting
blade
Brake
lever
Operator
presence bar
Handle bar

Operation (cont’d)
14
4. Grinding the Stump
WARNING: Flying Debris Hazard
Stones, chips, and debris can cause serious injury or property damage.
Debris can fly 75 ft in any direction out of the chute. They can bounce off
any fixed objects as well and hit operator, bystanders or breakable objects.
1. Set/engage the brake.
2. Pivot the grinder toward the side of the stump, then lower it approximately 1/2" to 1” into the
front-top corner of the stump. Slowly pivot the cutting blade back and forth, lowering the
cutting blade approximately 1/2” to 1” before each sweep, until you have removed the front
portion of the stump to ground level.
WARNING: Rotating cutter wheel.
Keep hands and feet away. Contact with wheel rotating teeth will cause
serious personal injury.
3. Raise cutting blade until center of cutting blade is just above top of stump.
4. With cutting blade off to one side, advance the machine horizontally by releasing and resetting
the brake. Advance the machine forward to engage the cutting blade into the stump so that
when swept across the stump it will remove 1/2" to 1” of stump with each sweep.
5. Sweep the cutting blade across the stump, cutting away 1/2” to 1” of stump.
6. Advance cutting blade 1/2” to 1”, and sweep again across stump in opposite direction.
7. Continue sweeping cutting blade left and right across stump, advancing it before each sweep,
cutting 1/2” to 1” depth of stump with each sweep.
8. Cut complete stump flush with ground, then go back and cut to further depth, if desired.
Chip Build-up
9. When grinding larger stumps, chips may begin to build up under the wheels.
Release brake and pull machine towards you so that the “chip pile” is directly under
the cutting wheel.
Drop cutter wheel down on “chip pile”, material will be discharged from machine
area.
WARNING: Flying Debris Hazard
Stones, chips, and debris can cause serious injury or property damage.
Debris can fly 75 ft in any direction out of the chute and bounce off objects
and hit operator, bystanders or breakable objects.
Direction of
grinding
Chip pile
Cutter wheel

Operation (cont’d)
15
On these larger stumps, DO NOT allow grinder wheels to drop into stump hole. If a hole
is in the way of your progress, fill it with chips or change position.
WARNING:
Stop engine and set brake before leaving operator’s position. KEEP
BRAKE ENGAGED except when changing locations.
10. When finished, stop the machine.
11. Pull machine away from stump, and rake chips away from stump.
5. Refueling
1) Before removing gas cap, turn engine off and allow to cool for at least two minutes.
Note: A running or hot engine can ignite fuel.
2) Remove grinder gasoline cap.
3) Add gasoline through the fill opening:
-Use only an UL-approved portable gasoline container to transfer the gasoline to the grinder’s
tank.
-Be aware of safety warning and instructions below for avoiding static electric caused fires.
WARNING:
Static electric spark hazard
A static electric spark can explosively ignite gasoline vapor,
resulting in a flash fire that could cause serious injury or death.
See “Special Safety Information on Static Electricity” at end of
this manual.
4) Clean up gasoline spills /splashes immediately.
If possible, move the grinder away from spilled gasoline on
the ground.
Wipe up spilled gasoline, and wait 5 minutes for excess
gasoline to evaporate before starting engine.
Gasoline soaked rags are flammable and should be disposed
of properly.
If gasoline is spilled on your skin or clothes, change clothes
NOT CORRECT
CORRECT
Wheel
Chip pile/debris
Hole

Operation (cont’d)
16
and wash skin immediately.
5) Replace gasoline cap securely before starting engine.
6) Store extra gasoline in a cool, dry place in an UL-approved, tightly sealed container.
7) Filling towable units or portable containers at service stations:
Even if you have a towable unit, avoid static electric sparking while filling the
gasoline tank:
Never fill the grinder’s gas tank directly from the fuel pump. The grinder’s tank
is not grounded and high velocity flow from the pump can cause static
electricity build-up. Use an approved portable container to transfer gas to the
grinder’s tank.
Use a portable container made of metal or conductive plastic. This is preferred
because it dissipates static charge to ground more readily.
Never fill a portable gas container while it is sitting inside a vehicle, trailer,
trunk, or pick-up truck bed. ALWAYS place container on the ground to be
filled.
Keep nozzle in contact with container while filling. Do not use a nozzle lock-
open device.
6. Storing the Grinder
When you are finished using the grinder and it has cooled, you must:
oCool engine before storage.
oClean the grinder.
oInspect for worn or damaged parts.
oChoose covered storage location.
oPrevent accidental starting.
oPlan on exercising the engine at least monthly unless the grinder is prepared for long-term
storage.
Detailed instructions are provided below.
Cool engine
Let engine cool for at least five minutes before storing. A hot engine can
be a fire hazard.
Clean grinder
Clean all grease, dirt, mud and other foreign matter from the machine.
Touch up paint damage to prevent rust.
Inspect grinder
Inspect the machine for worn or damaged parts and tighten any nuts or
screws that may have become loose. Pay particular attention to the
cutting teeth.
Choose a storage
location
Store the grinder in a location that is:
oClean and dry

Operation (cont’d)
17
oAway from sources of heat, open flames, sparks, or pilot lights, even
if the grinder’s gas tank is empty. Residual gasoline could ignite.
oAway from extreme high or low temperatures.
oCover it for extra protection
Remove key
Remove key from starter and secure key in a safe location, or remove
spark plug, in order to ensure the grinder cannot be started in a storage
location or by untrained persons or children.
Start grinder every
4 weeks
The grinder should be started regularly. At least every four weeks, start
the engine and let it run for 10 to 15 minutes.
Monthly exercising of the grinder will dry out any moisture that has
accumulated, lubricate cylinders, and clean out old gas in the carburetor.
Moisture, old gas, and dry mechanical parts cause deterioration in stored
engines.

Operation (cont’d)
18
Prepare engine for
long term
(seasonal) storage if
needed
If you will not be able to start the grinder regularly, you must prepare
the engine for long term storage to prevent gum deposits from forming
and causing malfunction of the engine.
Prepare engine for long term storage by:
oRemoving all gasoline from the tank and carburetor
OR
oAdding fuel stabilizer to the gasoline (following manufacturer’s
instructions)
Fuel stabilizer steps:
1. Ensure gas tank is full.
2. Add fuel stabilizer to fuel tank.
3. Run engine at least 10 minutes after adding stabilizer to
allow it to enter the fuel system.
4. Shut off engine
5. Disconnect spark plug wire and remove spark plug
6. Add one teaspoon oil through spark plug hole
7. Place rag over spark plug hole and turn starter (or pull the
recoil) a few times to lubricate the combustion chamber.
8. Replace spark plug, but do not reconnect the spark plug wire.
WARNING:Gasoline fire/explosion hazard
Gasoline is highly flammable and explosive. Drain the fuel into an
approved container OUTDOORS and far away from open flame.
NEVER store an engine with fuel in the tank indoors or in poorly
ventilated spaces where fuel vapor can come in contact with
static electric sparks
sparks from electric wiring, batteries, or running engines
sources of heat (such as a hot engine or exhaust)
open flames, including pilot lights

Maintenance & Repair
19
WARNING
ALWAYS shut off the engine, make sure the engine is cool, disconnect the spark plug and
positive battery terminal from the battery before cleaning, adjusting, or servicing the
grinder. Make sure all guards and shields are replaced before using.
Maintenance
Perform regular
maintenance
Perform periodic maintenance as directed in this manual to keep the
grinder in safe working condition.
Follow safety rules
Read and follow these safety rules whenever you will be servicing the
grinder:
Turn off grinder. Always turn off grinder and remove spark plug or spark
plug wire, and disconnect positive battery terminal from battery on electric
start models before working on the engine or grinder to prevent accidental
starting.
Replace guards/shields. Make sure all guards and shields are replaced after
servicing the grinder.
Burns. Muffler will be hot even after unit is stopped. Allow unit to cool
before servicing.
Repair. Major service, including the installation or replacement of parts,
should be performed only by a qualified electrical service technician. Obtain
factory approved parts from Dosko Customer Service at 1-800-822-0295.
Replacement parts. If a part needs replacement, only use factory approved
repair parts. Replacement parts that do not meet specifications may result in a
safety hazard or poor operation of the grinder and will void the warranty.
Perform engine
maintenance
Perform engine maintenance as specified in the engine owner’s manual.
Engine maintenance items include:
1. Oil and oil filter changing
2. Air filter check/replacement
3. Spark plug cleaning and replacement
4. Fuel filter check/replacement
5. Fuel tank cleaning.
Inspect fuel system
/ check for leaks
Inspect the fuel system and check for leaks on a regular basis.
Look for: signs of leaks or deterioration, chafed or spongy fuel hose, loose
connections, loose or missing fuel hose clamps, damaged gasoline tank, or
defective gasoline shut-off valve.
Lubricate
Cutter shaft bearings and wheel bearings should be greased.
The cutter shaft bearing is greased by pumping grease into zerks located on
the housing of the bearing.

Maintenance & Repair (cont’d)
20
The wheels should be greased by repacking the bearings inside the wheel
hub with grease.
Grease Specification
Soap Type
Lithium Complex
NLGI Grade
#2
Dropping Point
230°C (446°F)
Additives
Corrosion and Oxidation
inhibitors, EP optional
Viscosity Index
80 Minimum
Check and adjust
brake
Check that the brake is functioning properly.
-Lock the brake, push down on handle bar so that cutter wheel
is off the ground.
-Push or pull the grinder- if the brake is loose, the wheel will
rotate.
Grease zerks
Cutting
wheel
Bearing
Hub
Cotter
pin
Castle
nut
Dust
cap
Bearing
Washer
1. Remove existing cap, cotter
pin, castle nut, washer, and
hub off spindle.
2. Inspect inner and outer
bearing and pack with grease.
3. Slide hub and washer back
onto spindle.
4. Using a torque wrench,
tighten the castle nut 30-40
foot-lbs.
5. Loosen the castle nut until
loose enough to turn the
castle nut with your fingers.
6. Re-tighten the castle nut
finger tight.
7. Reinstall cotter pin and dust
cap.