2021 YAMAHA GP800R warning

4-1
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EJU00516a
Storage
WARNING
Always place the fuel cock knob in the
“OFF” position when storing the water-
craft, otherwise fuel could leak out into
the engine or engine compartment,
which would create a fire hazard.
Storage for prolonged periods of time,
such as winter storage, requires preventa-
tive maintenance to ensure against deterio-
ration. It is advisable to have the watercraft
serviced by a Yamaha dealer prior to stor-
age. However, the following procedures can
be performed by the owner.
EJU00913a
Flushing the cooling system
Flushing the cooling system is essential
to prevent the cooling system from being
clogged with salt, sand, or dirt.
CAUTION:
●Do not supply water to the cooling
water passages when the engine is not
running. The water could flow back
through the muffler into the crankcase
causing severe engine damage.
●Do not run the engine for more
15 seconds without supplying water,
otherwise the engine may overheat.

4-3
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EJU00526a
Lubrication
WARNING
To reduce the risk of fire or explosion:
Never pour or spray gasoline, or any sub-
stance other than engine fogging oil
through the holes in the carburetor
silencer cover.
CAUTION:
●Be sure to replace the caps securely
after fogging the engine. Otherwise
water could enter the engine and
cause damage.
●Do not attempt to run the engine at full
throttle or for more than 15 seconds
while the watercraft is out of the water,
otherwise the engine may overheat
and/or seize.
1. Open the silencer cap 1 on the silencer.
2. Start the engine with the watercraft in a
well-ventilated area.
3. With the engine running at a fast idle,
quickly spray as much fogging oil as pos-
sible through the hole in the silencer
cover. Keep spraying until the engine
stalls (or a maximum of 15 seconds).
4. Install the cap securely.
5. Remove the spark plugs and pour
approximately one tablespoon of engine
oil into each cylinder. Grease the spark
plug threads and install the spark plugs.
6. Crank the engine for 3 seconds.
7. Lubricate all cables such as the throttle,
choke, and steering cables.
8. Lubricate the areas of the watercraft
specified under Lubrication points on
page 4-16.

4-4
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EJU00946
Fuel system
Draining the fuel system prevents buildup
of varnishes and other harmful deposits that
result when gasoline sits for a prolonged
period of time.
WARNING@Gasoline is highly flammable and explo-
sive. A fire or explosion can cause
severe injury or death. Shut the engine
off. Drain in well-ventilated areas away
from flames or sparks. Do not smoke.
Avoid spilling gasoline. Wipe up spilled
gasoline immediately.
@
To drain the fuel system:
1. Place the fuel cock knob in the “OFF”
position.
2. Drain the fuel tank using a siphon.

4-7
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EJU00535a
Maintenance and
adjustments
Periodic inspection, adjustment and lubri-
cation will keep your watercraft in the safest
and most efficient condition possible. Safety
is an obligation of the watercraft owner. The
most important points of watercraft inspec-
tion, adjustment and lubrication are
explained on the following pages.
See your Yamaha dealer for genuine
Yamaha replacement parts and optional
accessories designed for your watercraft.
Remember that failures that are the result
of the installation of parts or accessories
which are not qualitatively equivalent to gen-
uine Yamaha parts are not covered by the
limited warranty.
WARNING
●Be sure to turn off the engine when
you perform maintenance unless oth-
erwise specified, otherwise an acci-
dent or injury could result from
unexpected operation, moving parts,
or electric shock. If the owner is not
familiar with watercraft servicing, this
work should be done by a Yamaha
dealer. Improperly serviced compo-
nents could fail or stop operating cor-
rectly, which could result in an
accident.
●Modifications to this watercraft not
approved by Yamaha may cause loss
of performance or excessive noise, or
render it unsafe for use. Consult a
Yamaha dealer before attempting any
changes.

4-10
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EJU00537
Inspecting the fuel system
WARNING
Gasoline and its vapors are highly flam-
mable and explosive.
Check the fuel system for leaks, cracks,
or malfunctions. If any problem is found, do
the necessary repair or replacement as
required. If repair is necessary, consult a
Yamaha dealer.
Check:
●Carburetor for leakage.
●Fuel pump for malfunction or leakage.
●Fuel tank for water or dirt.
●Fuel tank for damage, cracks or leakage.
●Fuel hose joint for leakage.
●Fuel hose for cracks or other damage.
●Fuel filter for leakage.
●Fuel cock for leakage.
●Air vent check valve for leakage.
●Fuel tank filler cap for damage.
WARNING
Failure to check for and repair any fuel
leakage may result in fire or explosion.

4-11
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EJU00538
Fuel filter
This watercraft is equipped with a one-
piece, disposable fuel filter 1. The fuel filter
should be replaced once a year or after
every 200 hours of operation, or if water is
found in the filter. Have a Yamaha dealer
replace the fuel filter if necessary.
WARNING
Do not try to replace the fuel filter your-
self. An incorrectly installed filter can
leak gasoline, which could lead to fire or
explosion. If necessary, have a Yamaha
dealer replace the fuel filter.
EJU00540
Fuel tank
Check the fuel tank 1 for leakage or
water in the tank. If water is found in the fuel
system or if the fuel tank needs to be
cleaned have a Yamaha dealer service the
watercraft.

4-16
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NOTE:
●Wipe off any water on the spark plug or
inside the cap before installing the spark
plug cap. Push the spark plug cap down
until it clicks.
●If a torque wrench is not available when
you are fitting a new spark plug, a good
estimate of the correct torque is 1/4 turn
to 1/2 turn past finger tight. Have the
spark plug adjusted to the correct torque
with a torque wrench as soon as possible.
WARNING
Be careful not to damage the insulator
when removing or installing a spark plug.
A damaged insulator could allow sparks
to escape, which could lead to explosion
or fire.
EJU00553a
Lubrication points
To keep moving parts sliding or rotating
smoothly, coat them with water-resistant
grease.
Recommended water resistant grease:
Yamaha Marine Grease/
Yamaha Grease A
●Throttle cable (carburetor end)
●Oil pump cable
●Choke cable (carburetor end)

4-19
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EJU00572
Inspecting the battery
Check the level of the battery electrolyte
and make sure the leads are secure.
WARNING
Battery electrolyte is poisonous and dan-
gerous, causing severe burns, etc. Elec-
trolyte contains sulfuric acid. Avoid
contact with skin, eyes or clothing.
Antidotes
External: Flush with water.
Internal: Drink large quantities of water
or milk. Follow with milk of magnesia,
beaten egg or vegetable oil. Call physi-
cian immediately.
Eyes: Flush with water for 15 minutes
and get prompt medical attention.
Batteries produce explosive gases. Keep
sparks, flame, cigarettes, etc., well away.
If using or charging the battery in an
enclosed space, make sure that it is well
ventilated. Always shield your eyes when
working near batteries.
KEEP OUT OF THE REACH OF CHIL-
DREN.
CAUTION:
Be careful not to place the battery on its
side.
Make sure to remove the battery from the
battery compartment when adding bat-
tery electrolyte or charging the battery.
When checking the battery, make sure
the breather hose is connected to the
battery and not obstructed.