2021 YAMAHA GP800R battery

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1Spark plugs/Spark plug caps
2Electrical box
Protects electrical components from water.
3Flush hose connector
Use to flush the engine cooling water pas-
sages.
4Spark plug lead
5Muffler
6Fuel filter
7Fuel tank8Oil tank
9Battery
0Fire extinguisher container
AWater separator

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EJU00386a
Fuel meter
The fuel meter is provided for convenient
fuel level checking while riding. The fuel
meter has eight segments which show the
amount of fuel remaining in the fuel tank.
NOTE:
The indication of the segments differs on
your operating condition. Use the meter as a
reference.
EJU00390a
Hour meter
The hour meter is provided to make it
easy to follow the maintenance schedule.
The meter shows the hours of engine opera-
tion that have elapsed since the watercraft
was new.
NOTE:
●The elapsed time will be kept even if the
battery terminals have been discon-
nected.
●If the hour meter malfunctions, “____”
display and the warning light will blink.

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EJU00422
Pre-operation checks
Pre-operation check list
Before operating this watercraft, perform the checks in the following check list. See the
accompanying text in this chapter for details on how to perform the checks.
WARNING
If any item in the pre-operation check list is not working properly, have it inspected
and repaired before operating the watercraft, otherwise an accident could occur.
NOTE:
Pre-operation checks should be made thoroughly each time the watercraft is used. This pro-
cedure can be completed in a short time. It is worth the time spent to assure safety and reli-
ability.
ITEM ROUTINE PAGE
Engine compartment Remove the seat and front storage compartment
to ventilate engine compartment. Check for fuel
vapors or loose electrical connections3-6
Bilge Check for water and fuel residue and remove if
necessary3-7
Throttle Check that the throttle lever springs back 3-10
Steering system Check for proper steering system operation 3-10
Fuel and oil Check fuel and oil level and add if necessary
Check hoses and tanks for leakage3-6
Water separator Check for water and drain if necessary 3-7
Battery Check electrolyte level and battery condition 3-8
Hood Check that the hood is properly secured 2-6
Seat Check that the seat is properly secured 2-5
Hull/Deck Check the hull and deck for cracks or other dam-
age—
Jet unit Check for debris and remove if necessary 3-11
Fire extinguisher Check the condition and replace if necessary 3-9
Engine shut-off cord Check condition and replace is frayed or broken 3-11
Switches Check the start switch, engine stop switch and
engine shut-off switch for proper operation when
the watercraft is in the water3-12
Cooling water pilot outlet Check that water is discharged while the engine
is running and the watercraft is in the water3-12
Multifunction information center Check for warning indications and proper opera-
tion3-12

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EJU00435a
Battery
Check the battery condition and the elec-
trolyte level.
Check that the battery leads are tightened
securely and there is no corrosion on the
battery terminals.
WARNING
The battery must always be fully charged
and in good condition. Loss of battery
power may leave you stranded. Never
operate the watercraft if the battery does
not have sufficient power to start the
engine or if it shows any other signs of
decreased power.
Make sure that the breather hose is prop-
erly connected and that it is not damaged or
obstructed.
Make sure that the battery is securely
held in place.
1
Positive (+): Red lead
2
Negative (–): Black lead
3
Breather hose

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F0P03010
EJU00728
Fire extinguisher
Check that there is a full fire extinguisher
on board. The fire extinguisher container 1
is located in the battery compartment.
To open the fire extinguisher container
cap2 remove the seat and turn it counter-
clockwise.
After inserting the fire extinguisher make
sure that the container cap is tightened
securely.
NOTE:
●See the instructions supplied by the fire
extinguisher manufacturer for checking
the fire extinguisher. Always keep the
extinguisher in the fire extinguisher con-
tainer.
●Always carry a fire extinguisher on board.
A fire extinguisher is not standard equip-
ment with this watercraft. If you do not
have one, contact a Yamaha dealer or a
fire extinguisher dealer to obtain one
meeting the proper specifications.

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5. While lightly squeezing the throttle lever,
push the start switch (green button).
WARNING
On this watercraft, the engine is con-
nected directly to the jet pump. Starting
the engine immediately generates some
thrust. Apply only enough throttle to
keep the engine running.
6. Release the start switch as soon as the
engine starts to run.
CAUTION:
●Never push the start switch while the
engine is running.
●Do not operate the start switch for
more than 5 seconds, otherwise the
battery will be discharged and the
engine will not start. Also, the starter
motor may be damaged. If the engine
does not start in 5 seconds, release
the start switch, wait 15 seconds, and
try again.
7. After the engine has warmed up, move
the choke lever back to its original posi-
tion.
NOTE:
If the choke lever is left turned on, the
engine will stall.

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EJU00515
MAINTENANCE AND
CARE
Storage....................................................... 4-1
Flushing the cooling system ................... 4-1
Lubrication............................................... 4-3
Fuel system............................................. 4-4
Battery ..................................................... 4-5
Cleaning the watercraft........................... 4-6
Maintenance and adjustments............... 4-7
Owner’s/Operator’s Manual and tool
kit ............................................................. 4-8
Periodic maintenance chart .................... 4-9
Inspecting the fuel system .................... 4-10
Inspecting the oil injection system........ 4-12
Inspecting the steering cable................ 4-13
Inspecting and adjusting the throttle
cable ...................................................... 4-13
Inspecting the QSTS mechanism ........ 4-14
Cleaning and adjusting the spark
plugs ...................................................... 4-15
Lubrication points .................................. 4-16
Inspecting the battery ........................... 4-19
Adjusting the carburetor ....................... 4-21
Replacing the fuse ................................ 4-22
Bleeding the oil injection pump............. 4-22
Adjusting the Yamaha Adjustable
Sponson (Y.A.S.) .................................. 4-23
Specifications......................................... 4-24

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Battery
If the watercraft is not used for a month or
more, disconnect the (–) battery cable first,
and then the (+) cable and breather pipe,
and next remove the battery from the craft.
Clean the battery casing using fresh
water.
If the battery terminals are dirty or cor-
roded, clean the mating surfaces on the ter-
minals for the battery cables using the wiring
brush or equivalents.
Recharge the battery, and then store it in
a cool and dark place.
Apply the Yamaha marine grease/Yamaha
grease A to the battery terminals.
Recharge the battery periodically at least
2 months because a battery will discharge
electricity by itself while storing.
CAUTION:
The battery may be impossible to use
again if you store it for a longer time
without recharging. Recharge the battery
periodically.
NOTE:
The battery condition can be found by
checking the specific gravity of the electro-
lyte. However, you can also know the battery
condition roughly by measuring the voltage
at both battery terminals. Recharge the bat-
tery if the voltage is 12 volts or less.
Yamaha recommend checking the specific
gravity of the electrolyte and charging bat-
tery by a Yamaha dealer or a battery dealer.
If you maintain the battery yourself, read
carefully the instructions for the tool and
machine before maintenance.
Specific gravity of electrolyte
(for reference):
1.28 at 20 °C (68 °F)