Bohmer-AG GRX8000-3G User manual

GRX8000-3G
READ THIS MANUAL CAREFULLY BEFORE USE – FAILURE TO DO SO MAY RESULT IN INJURY, PROPERTY DAMAGE
AND MAY VOID WARRANTY. • KEEP THIS MANUAL FOR FUTURE REFERENCE. • Products covered by this manual may
vary in appearance, assembly, inclusions, specifications, description and packaging.
V 1.0
Gasoline Generator
GRX8000-3G

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Contents
SAFETY
COMPONENT IDENTIFICATION
CONTROLS
1) Engine Switch
2) Recoil Starter
3) Fuel Valve
4) Choke
5) Circuit Breaker
6) Ground Terminal
7) Oil Alert System
GENERATOR USE
1) Connections to a Building's Electrical System
2) Ground System
3) AC Applications
4) AC Operation
5) DC Operation
6) High Altitude Operation
PRE-OPERATION CHECK
1) Engine Oil
2) Fuel Recommendation
STARTING / STOPPING THE ENGINE
MAINTENANCE
1) Maintenance Schedule
2) Tool Kit
3) Engine Oil Change
4) Air Cleaner Service
5) Fuel Sediment Cup Cleaning
6) Spark Plug Service
TRANSPORTING / STORAGE
TROUBLESHOOTING
WIRING DIAGRAM
SPECIFICATIONS
CE DECLARATION OF CONFORMITY
3
3
4-8
8
12
15
19
21
23
25
26

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Caution: In order to prevent accident. Please add the manostat when using the household
appliance or precision instruments
Congratulations on purchasing your new Bohmer generator. We want to help you get the best
results from your new generator and to operate it safely.
This manual contains the information on how to do that: please read it carefully.
All information and specifications in this publication is based on the latest product information
available at the time of printing. We reserve the right to make changes at any time without notice
and without incurring any obligation. No part of this publication may be reproduced without
written permission.
This manual should be considered a permanent part of the generator and should remain with it
if it is resold.
Safety Messages
Your safety and the safety of others are very important. We have provided important safety
messages in this manual and on the generator. Please read these messages carefully.
A safety message alerts you to potential hazards that could hurt you or others. Each safety
message is preceded by a safety alert symbol & and one of three words: DANGER, WARNING,
or CAUTION.
The meanings are:
DANGER: You WILL be KILLED or SERIOUSLY HURT If you don't follow instructions.
WARNING: You CAN be KILLED or SERIOUSLY HURT If you don't follow instructions.
CAUTION: You CAN be HURT if you don't follow instructions.
Damage Prevention Messages
Other important messages are preceded by the word NOTICE. This word means:
NOTICE: Your generator or other property could be damaged if you don't follow instructions.
The purpose of these messages is to help prevent damage to your generator, other property or
the environment.
General Safety Information

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Safety
The generators are designed to give safe and dependable service if operated according to
instructions. Read and understand this owner's manual before operating your generator. You
can help prevent accidents by being familiar with your generator's controls, and by observing
safe operating procedures.
Operator Responsibility
Know how to stop the generator quickly in case of emergency.
Understand the use of all generator controls, output receptacles, and connections. Be sure that
anyone who operates the generator receives proper instruction. Do not let children operate the
generator without parental supervision. Keep children and pets away from the area of operation.
Place the generator on a firm, level surface and avoid loose sand or snow. If the generator is
tilted or overturned. Fuel spillage may result. Also. If the generator is overturned or sinks into a
soft surface, sand, dirt, or water may enter the generator.
Carbon Monoxide Hazards
Exhaust contains poisonous carbon monoxide, a colourless and odourless gas. Breathing
exhaust can cause loss of consciousness and may lead to death.
If you run the generator in an area that is confined, or even partially enclosed, the air you
breathe could contain a dangerous amount of exhaust gas. To keep exhaust gas from building
up, provide adequate ventilation.
Electric Shock Hazards
The generator produces enough electric power to cause a serious shock or electrocution
if misused.
Using a generator or electrical appliance in wet conditions. Such as rain or snow, or near a
pool or sprinkler system, or when your hands are wet, could result in electrocution. Keep the
generator dry.
If the generator is stored outdoors, unprotected from the weather, check all electrical
components on the control panel, before each use. Moisture or ice can cause a malfunction or
short circuit in electrical components which could result in electrocution.
Do not connect to a building's electrical system unless an isolation switch has been installed by
a qualified electrician.

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Fire and Burn Hazards
The exhaust system gets hot enough to ignite some materials.
Keep the generator at least 1meter (3 feet) away from buildings and other equipment
during operation.
Do not enclose the generator in any structure.
Keep flammable materials away from the generator.
The muffler becomes very hot during operation and remains hot for a while after stopping the
engine. Be careful not to touch the muffler while it Is hot. Let the engine cool before storing the
generator indoors.
Gasoline is extremely flammable and is explosive under certain conditions. Do not smoke or
allow flames or sparks where the generator is refuelled or where gasoline is stored. Refuel in a
well-ventilated area with the engine stopped.
Fuel vapours are extremely flammable and may ignite after the engine has started.
Make sure that any spilled fuel has been wiped up before starting the generator.
Component Identification
Note: Diagrams may vary according to the types.

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1) Engine Switch
To start and stop engine.
Switch position:
OFF: To stop the engine. Key can be removed/inserted.
ON: To run the engine after starting.
START: To start the engine by turning the starter motor.
Return the key to the ON position once the engine has started. Do not use the starter for more
than 5 seconds at a time. If the engine fails to start, release the switch and wait 10 seconds
before operating the starter again.
2) Recoil Starter
To start the engine, pull the starter grip lightly until resistance is felt, then pull briskly
Notice: Do not allow the starter to snap back
against the engine. Return it gently to prevent
damage to the starter.
Controls
With Electric Starter Without Electric Started

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3) Fuel Value
The Fuel Valve is located between the fuel tank and carburettor. When the valve lever is in the
ON position, fuel is allowed to flow from the fuel tank to the carburettor. Be sure to return the
lever to the OFF position after stopping the engine.
4) Choke
The choke is used to provide an enriched fuel mixture when starting a cold engine. It can be
opened and closed by operating the choke lever or choke rod manually.
Move the lever or the rod to the CLOSE position to enrich the mixture.
5) Circuit Breaker
The circuit breaker will automatically switch OFF if there is a short circuit or a significant
overload of the generator at the receptacle. If the circuit breaker is switched OFF automatically,
check that the appliance is working properly and does not exceed the rated load capacity of the
circuit before switching the circuit breaker ON again.
The circuit breaker may be used to switch the generator power ON or OFF.

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6) Ground Terminal
The generator ground terminal is connected to the panel of the generator, the metal non-current
carrying parts of the generator, and the ground terminals of each receptacle. Before using
the ground terminal, consult a qualified electrician, electrical inspector or local agency having
jurisdiction for local codes or ordinances that apply to the intended use of the generator.
7) Oil Alert System
The oil alert system is designed to prevent engine damage caused by an insufficient amount
of oil in the crankcase. Before the oil level in the crankcase can fall below a safe limit, the oil
alert system will automatically shut down the engine (the engine switch will remain in the
ON position). The oil alert system shuts down the engine and the engine will not start. If this
occurs, first-check engine oil.
Generator Use
1) Connections to a Building's Electrical System
Connections for standby power to a building's electrical system must be made by a qualified
electrician. The connection must isolate the generator power from utility power and must
comply with all applicable laws and electrical codes.
Warning: Improper connection to a building's electrical system, can allow electrical current
from the generator to feedback into the utility lines. Such feedback may electrocute utility
company workers or others who contact the lines during a power outage. Consult the utility
company or a qualified electrician.
Caution: Make sure the engine oil level is just on the threads. Running the engine with too low
or high oil can damage the generator.
2) Ground System
To prevent electrical shock from faulty appliances, the generator
should be grounded. Connect a length of heavy wire between the
ground terminal and the ground source. The generators have a
system ground that connects generator frame components to the
ground terminals in the AC output receptacles. The system ground
is not connected to the AC neutral wire. If the generator is tested
by a receptacle tester, it will not show the same ground circuit
condition as for a home receptacle.

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Special Requirements
There may be Federal or State Occupational Safety and Health Administration (OSHA)
regulations, local codes, or ordinances that apply to the intended use of the generator. Please
consult a qualified electrician, electrical inspector, or the local agency having jurisdiction.
• In some areas, generators are required to be registered with local utility companies.
• If the generator is used at a construction site, there may be additional regulations which
must be observed.
3) AC Applications
Before connecting an appliance or power cord to the generator:
Make sure that it is in good working order. Faulty appliances or power cords can create a
potential for electrical shock.
If an appliance begins to operate abnormally, becomes sluggish or stops suddenly, turn it off
immediately. Disconnect the appliance, and determine whether the problem is the appliance, or
if the rated load capacity of the generator has been exceeded.
Make sure that the electrical rating of the tool or appliance does not exceed that of the
generator. Never exceed the maximum power rating of the generator. Power levels between
rated and maximum may be used for no more than 30 minutes.
Notice: Substantial overloading will switch off the circuit breaker. Exceeding the time limit for
maximum power operation or slightly overloading the generator may not switch the circuit
breaker OFF, but will shorten the service life of the generator.
Limit operation requiring maximum power to 30 minutes.
For continuous operation, do not exceed the rated power.
In either case, the total power requirements (VA) of all appliances connected must be
considered. Appliance and power tool manufacturers usually list rating information near the
model number or serial number.
4) AC Operation
1) Start the engine
2) Switch the AC circuit breaker ON.
3) Plug in the appliance.
Most motorized appliances require more than their rated wattage
for start-up.

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Do not exceed the current limit specified for any one receptacle. If an overloaded circuit causes
the AC circuit breaker to switch OFF. reduce the electrical load on the circuit, wait a few minutes
and then reset the circuit breaker.
5) DC Opertation
DC Terminals
The DC terminals may ONLY be used for charging 12-volt automotive type batteries. The
terminals are coloured red to identify the positive (+) terminal and black to identify the
negative (-) terminal. The battery must be connected to the generator DC terminals with
the proper polarity (battery positive to generator red terminal and battery negative to the
generator black terminal).
DC Circuit Protector (or DC Fuse)
The DC Circuit Protector (or DC Fuse) automatically shuts off the DC battery charging circuit
when the DC circuit is overloaded, when there is a problem with the battery, or the connections
between the battery and the generator are improper.
The indicator inside the DC circuit protector button will pop out to show that the DC circuit has
switched off. Wait a few minutes and push the button in to reset the DC Circuit protector.
Connecting the battery cables:

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1) Before connecting charging cables to a battery that is installed in a vehicle disconnect the
vehicle's grounded battery cable.
Warning: The battery gives off explosive gases; keep spark, flames and cigarettes away.
Provide adequate ventilation when charging or using batteries.
2) Connect the positive (+) battery cable to the battery positive (+) terminal.
3) Connect the other end of the positive (+) battery cable to the generator GI.
4) Connect the negative (-) battery cable to the battery negative (-) terminal.
5) Connect the other end of the negative (-) battery cable to the generator
6) Start the generator.
Notice: Do not start the vehicle while the battery charging cables are connected and the
generator is running. The vehicle or the generator may be damaged.
An overloaded DC circuit will fuse the DC fuse, if this happens, replace fuse. An overloaded
DC circuit, excessive current draw by the battery, or a wiring problem will trip the DC circuit
protector (PUSH button extends out). If this happens, wail a few minutes before pushing in the
circuit protector to resume operation. If the circuit protector continues to go OFF, discontinue
charging and see your authorized generator dealer.
Connecting the battery cables:
1) Stop the engine
2) Disconnect the negative (-) battery cable from the generator negative (-) terminal.
3) Disconnect the other end of the negative (-) battery cable from the battery negative (-)
terminal.
4. Disconnect the positive (+) battery cable from the generator positive (+) terminal.
5) Disconnect the other end of the positive (+) battery cable to the battery positive (+)
terminal.
6) Connect the vehicle ground cable to the battery negative (-) terminal.
7) Reconnect the vehicle grounded battery cable.
6) High Altitude Operation
At high altitude, the standard carburettor air-fuel mixture will be excessively rich. Performance
will decrease, and fuel consumption will increase. High altitude performance can be improved
by installing a smaller diameter main fuel jet in the carburettor and readjusting the pilot screw.
If you always operate the engine at altitudes higher than 5000 feet (1500 meters) above sea
level, have an authorized generator dealer perform this carburettor modification.
Even with suitable carburettor jetting, engine horsepower will decrease approximately 3.5% for

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each 1000 foot (300 meter) increase in altitude. The effect of altitude on horsepower will be
greater than this if no carburettor modification is made.
Notice: If an engine jetted for high altitude is used at a lower altitude, the lean air fuel mixture
will reduce performance and may over-heat and seriously damage the engine.
1) Engine oil
Notice: Engine oil is a major factor affecting
engine performance and service life. Non-
detergent and 2-stroke engine oils will damage
the engine and are not recommended.
Use 4-stroke oil, or equivalent high detergent,
premium quality motor oil AMBIENT
TEMPERATURE certified to meet or exceed U.S.
automobile manufacturers requirements for Service Classification SG. SF/CC, CD. Motor oils
classified SG, SF/CC, CD will show this designation on the container.
SAE 10W-30 is recommended for general temperature use. Other viscosities shown in the
chart may be used when the average temperature in your area is within the indicated range.
1) Remove the oil filler cap and wipe the dipstick clean.
2) Check the oil level by inserting the dipstick into the tiller neck without screwing it in.
3) If the level is low, add the recommended oil to the upper mark on the dipstick.
Pre-Operation Check

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2) Fuel Recommendation
1. Check the fuel level gauge.
2. Refill the tank if the fuel level is low. Do not fill above the shoulder of the fuel strainer.
Warning: - Gasoline is extremely flammable and is explosive under certain conditions.
- Refuel in a well-ventilated area with the engine stopped.
- Do not smoke or allow flames or sparks in the area where the engine is
refuelled or where gasoline is stored.
- Do not overfill the fuel tank (there should be no fuel in the filler neck). After
refuelling, make sure the tank cap is closed properly and securely. Be careful
not to spill fuel when refuelling. Spilled fuel or fuel vapour may ignite. If any
fuel is spilled, make sure the area is dry before starting the engine.
- Avoid repeated or prolonged contact with skin or breathing of vapour.
- KEEP OUT OF REACH OF CHILDREN.
Use gasoline with a pump octane rating of 86 or higher.
We recommend unleaded gasoline because it produces fewer engine and spark plug deposits
and extends exhaust system life.
Never use stale or contaminated gasoline or oil/gasoline mixture. Avoid getting dirt or water in
the fuel tank.
Occasionally you may hear light "spark knock" or "pinging" (metallic rapping noise) while
operating under heavy loads. This is no cause for concern.
If spark knock or pinging occurs at a steady engine speed, under normal load, change brands
of gasoline. If spark knock or pinging persists, see an authorized generator dealer.

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Notice: Running the engine with persistent spark knock or pinging can cause engine damage.
Running the engine with persistent spark knock or pinging is misuse, and the Distributor’s
Limited Warranty does not cover parts damaged by misuse.
Oxygenated Fuels
Some gasoline is blended with alcohol or an ether compound to increase the octane. These
gasolines are collectively referred to as oxygenated fuels. Some areas of the United States use
oxygenated fuels to help meet clean air standards.
If you use an oxygenated fuel, be sure its pump octane rating is 86 or higher.
Ethanol (ethyl or grain alcohol)
Gasoline containing more than 10% ethanol by volume may cause starting or performance
problems. Gasoline containing ethanol may be marketed under the name "Gasohol".
Methanol (methyl or wood alcohol)
Gasoline containing methanol must contain cosolvents and corrosion inhibitors to protect the
fuel system. Gasoline containing more than 5% methanol by volume may cause startin8 and/or
performance problems and may damage metal, rubber and plastic parts of your fuel system.
MTBE (methyl tertiary butyl ether)
You may use gasoline containing up to 15% MTBE by volume. Before using an oxygenated
fuel, try to confirm the fuel's contents. Some states (provinces in Canada) require this
information to be posted on the pump. If you notice any undesirable operating symptoms,
switch to a conventional unleaded gasoline. Fuel system damage or performance problems
resulting from the use of an oxygenated fuel are not our responsibility and are not covered
under warranty.
Notice: Oxygenated fuels can damage paint and plastic. Be careful not to spill fuel when filling
your fuel tank. Damage caused by spilled fuel is not covered under warranty.

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Starting and stopping the engine
Starting the engine
1. Make sure that the AC circuit breaker is in the OFF position.
The generator may be hard to start if a load is connected.
2. Turn the fuel valve to the ON position.
3. Turn the choke lever or to the CLOSE position, or pull the choke rod out to the CLOSE
position.
4. Start the engine
With electric starter: (Optional kit)
Turn the engine switch to the START position and hold it there for 5 seconds or until the
engine starts.
Notice: Operating the starter motor for more than 5 seconds can damage the motor. If the
engine fails to start, release the switch and wait 10 seconds before operating the starter again.
If the speed of the starter motor drops after a period of time, it indicates that the battery
should be recharged.
When the engine starts, allow the engine switch to return to the ON position.
5. Turn the choke lever or push the choke rod to the OPEN position as the engine warms up.
Starting the engine
In an emergency:
To stop the engine in an emergency, move the engine switch to the OFF position.
In normal use:
1. Turn the AC circuit breaker to the OFF position.
2. Disconnect the DC battery charging cables.
3. Turn the engine switch to the OFF position.
4. Turn the fuel valve to the OFF position.

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Maintenance
Good maintenance is essential for safe, economical, and trouble-free operation. It will also
help reduce air pollution.
Warning: Exhaust gas contains poisonous carbon monoxide. Shut off the engine before
performing any maintenance. If the engine must be run, make sure the area is well ventilated.
Periodic maintenance and adjustment are necessary to keep the generator in good operating
condition. Perform the service and inspection at the intervals shown in the Maintenance
schedule below.
1) Maintenance Schedule
1) Service more frequently when used in dusty areas.
2) These items should be serviced by an authorized generator dealer, unless the owner has the
proper tools and is mechanically proficient.
3) For professional commercial use, long hours of operation to determine proper
maintenance intervals.
Warning: Improper maintenance, or failure to correct a problem before Operation, can cause
a malfunction in which you can be seriously hurt or killed. Always follow the inspection and
maintenance recommendations and schedules in this owner's manual.
The maintenance schedule applies to normal operating conditions. If you operate your
generator under severe conditions, such as sustained high-toad or high-temperature
operation, or use it in unusually wet or dusty conditions, consult your servicing dealer for
recommendations applicable to your individual needs and use.

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Tool kit
The tools supplied with the generator will help you to perform the owner maintenance
procedures listed on the following page. Always keep this tool kit with the generator.
2) Air Cleaner Service
A dirty air cleaner will restrict air flow to the carburettor. To prevent carburettor malfunction.
Service the air cleaner regularly. Service more frequently when operating the generator in
extremely dusty areas
Warning: Using gasoline or flammable solvent to clean
the filter element can cause a fire or explosion. Use only
soapy water or non-flammable solvent.
Notice: Never run the generator without the air cleaner.
Rapid engine wear will result.
1. Unsnap the air cleaner cover clips, remove the air
cleaner cover, and remove the element.
2. Wash the element in a solution of household detergent
and warm water, then rinse thoroughly; or wash in
non-flammable or high flash point solvent. Allow the
element to dry thoroughly.
3. Soak the element in clean engine oil and squeeze out
the excess oil. The engine will smoke during initial
start-up It too much oil is left in the element.
4. Reinstall the air cleaner element and the cover.

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3) Fuel Sediment Cup Cleaning
The sediment cup prevents dirt or water which may
be in the fuel tank from entering the carburettor.
If the engine has not been run for a long time, the
sediment cup should be cleaned.
1. Turn the fuel valve to the OFF position.
2. Clean the sediment cup, and O-ring, in non-
flammable or high flash point solvent.
3. Reinstall O-ring, and sediment cup.
4. Turn the fuel valve ON and check for leaks.
6) Spark Plug Service
Recommended spark plugs: F5T or F6TC or F7TJC
or other equivalents
To ensure proper engine operation, the spark plug must be properly gapped and free of
deposits.
If the engine has been running, the muffler will be very hot. Be careful not to touch the muffler.
1. Remove the spark plug cap.
2. Clean any dirt from around the spark plug base.
3. Use the wrench supplied in the tool kit to remove the spark plug.
4. Visually inspect the spark plug. Discard it if the insulator is
cracked or chipped. Clean the spark plug with a wire brush if it
is to be reused.
5. Measure the plug gap with a feeler gauge. Correct as
necessary by carefully bending the side electrode.
The gap should be: 0.70-0.80 mm (0.028-0.031 in).

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6. Check that the spark plug washer is in good condition, and thread the spark plug in by hand
to prevent cross-threading.
7. After the spark plug is seated, tighten with a spark plug wrench to compress the washer.
If installing a new spark plug, tighten 1/2 turn after the spark plug seats to compress the
washer. If reinstalling a used spark plug, tighten 1/8 -1/4 turn after the spark plug seats to
compress the washer.
Notice: The spark plug must be securely tightened. An Improperly tightened spark plug can
become very hot and could damage the engine. Never use spark plugs which have an improper
heat range. Use only the recommended spark plugs or equivalent.
Transport and Storage
When transporting the generator, turn the engine switch and the fuel valve OFF. Keep the
generator level to prevent fuel spillage. Fuel vapour or spilled fuel may ignite.
STORAGE TIME RECOMMENDED SERVICE PROCEDURE TO PREVENT HARD
STARTING
Less than 1 month No preparation required
1 to 2 months Fill with fresh gasoline and add gasoline conditioner
2 months to 1 year Fill with fresh gasoline and add gasoline conditioners Drain the
carburettor float bowl Drain the fuel sediment cup
1 year or more Fill with fresh gasoline and add gasoline conditioners
Drain the carburettor float bowl
Drain the fuel sediment cup
Remove the spark plug.
Put a tablespoon of engine oil into the cylinder.
Tum the engine slowly with the pull rope to distribute the oil.
Reinstall the spark.
Change the engine oil After removal from storage, drain the stored
gasoline into a suitable container, and fill with fresh gasoline
before starting.
Use gasoline conditioners that are formulated to extend storage life. Contact your authorized
generator dealer for conditioner recommendations.

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Warning: Contact with a hot engine or exhaust system can cause serious burns or fires. Let the
engine cool before transporting or storing the generator.
Take care not to drop or strike the generator when transporting Do not place heavy objects on
the generator.
Before storing the unit for an extended period:
• Be sure the storage area is free of excessive humidity and dust.
• Service according to the table below:
1. Drain the carburettor by loosening the drain screw. Drain the gasoline into a suitable container.
Warning: Gasoline is extremely flammable and is explosive under certain conditions. Perform
this task in a well-ventilated area with the engine stopped. Do not smoke or allow flames or
sparks in the area during this procedure.
2. Change the engine oil.
3. Remove the spark plug, and pour about a
tablespoon of clean engine oil into the cylinder.
Crank the engine several revolutions to distribute
the oil, then reinstall the spark plug.
4. Slowly pull the starter grip until resistance is
felt. At this point, the piston is coming up on its
compression stroke and both the in-take
and exhaust valves are closed. Storing the
engine in this position will help to protect it
from internal corrosion.