2021 YAMAHA GP800R engine

3-5
E
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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EJU00426
Pre-operation check points
Engine compartment
Ventilate the engine compar tment before
each use.
To ventilate the engine compartment,
remove seat and front storage compart-
ment. (See page 2-5 for seat, and 2-19 for
front storage compartment.) Allow the
engine compartment to remain open for a
few minutes to allow any fuel vapors to
escape. Also, check for loose electrical con-
nections.
WARNING
Failure to ventilate the engine compart-
ment could result in fire or explosion. Do
not start the engine if there is a fuel leak
or a loose electrical connection.
EJU00427-30a
Fuel and oil systems
Check the fuel system for leakage, cracks
or malfunctions before each use. (See page
4-9 for check points and correct proce-
dures.)
1. Remove the fuel tank filler cap to release
any pressure that might have built up in
the fuel tank.
2. Remove seat and front storage compart-
ment. (See page 2-5 for seat, and 2-19
for front storage compartment.)
3. Check the fuel and oil levels in the tanks
and replenish if necessary. (See page 3-3
for filling instructions.)
4. Turn the fuel cock to the “ON” position.

3-7
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EJU00432a
Water separator
Check the water separator 1 for water.
Normally the water separator is empty. The
water separator retains any water entering
through the fuel tank breather hose if the
watercraft is capsized.
If water remains in the water separator,
drain it by removing the drain screw 2.
Install the drain screw again after draining
the water separator.
EJU00433a
Bilge
Check for moisture and fuel residue in the
bilge.
Excessive water in the bilge can splash
into the carburetor and engine which could
cause engine damage.
To remove water from the bilge:
1. Remove the stern drain plugs.
2. Raise the bow of the watercraft until the
water drains.
3. After the water has drained, wipe the
bilge with dry rags to make sure that the
bilge is thoroughly dry.
4. Install the drain plugs.
CAUTION:
●Make sure that the stern drain plugs
are tightened securely before launch-
ing the watercraft.
●Clean any foreign materials, such as
dirt or sand, from the drain plug
threads before installing the drain
plugs.

3-8
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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

3-10
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EJU00447
Throttle
Squeeze and release the throttle lever
several times to make sure that there is no
hesitation in its travel. It should be smooth
over the complete range, and spring back to
the idle position when released.
WARNING
Before starting the engine, always check
the operation of the throttle lever. It
should move smoothly through its full
range of operation, and should spring
back to the idle position when released.
EJU00448
Steering system
Check for looseness in the handlebars.
Turn them as far as possible to the right
and left to make sure that operation is
smooth and unrestricted throughout the
whole range. Make sure that the jet thrust
nozzle also changes directions as the han-
dlebars are turned, and that there is no free
play between the handlebars and the jet
thrust nozzle.

3-11
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EJU00451a
Jet unit
Carefully check the jet intake for weeds,
debris, or anything else that might restrict
the intake of water. If the intake is clogged,
cavitation could occur, reducing jet thrust,
and possibly damaging the jet pump.
In some cases, the engine may overheat
because of lack of cooling water, and dam-
age to the engine could result. Engine cool-
ing water is fed to the engine by the jet
pump. (See page 5-4 for jet intake cleaning
procedures.)
WARNING
●Keep away from intake grate while
engine is on. Items such as long hair,
loose clothing, or PFD straps can
become entangled in moving parts
resulting in severe injury or drowning.
●Stop the engine and remove the clip
from the engine shut-off switch before
removing any debris or weeds, which
may have collected around the jet
intake.
EJU00004n
Engine shut-off cord (lanyard)
Check that the engine shut-off cord is not
frayed or broken. If the cord is damaged,
replace it; never try to repair it or tie it
together.

3-12
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RESET
WARNING
YAMAHA8
7
6
5
4
3
2
1km/hFUELHOUR
x1000r/min
MULTI
DISPLAY
F0X0225E
EJU00452a
Switches
Check the start switch 1, the engine stop
switch 2, and the engine shut-off switch 3
for proper operation.
To check these switches place the water-
craft in the water to provide adequate cooling.
Start the engine, and then pull the engine
shut-off cord 5 to remove the clip 4 from the
engine shut-off switch. Verify that the engine
stops immediately. (See pages 3-15 to 3-18
for information on proper operation of the
start switch, the engine stop switch and the
engine shut-off switch.)
EJU00453
Cooling water pilot outlet
Check that water comes out from the out-
lets while the engine is running and the
watercraft is in the water.
EJU00454
Multifunction information center
Check the operation of the multifunction
information center. (See pages 2-15 to 2-18
for multifunction information center.)

3-13
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EJU00676a
Operation
WARNING
Before operating your watercraft,
become familiar with all controls. Con-
sult your Yamaha dealer about any con-
trol or function you do not fully
understand. Failure to understand how
controls work could cause an accident or
prevent you from avoiding an accident.
CAUTION:
Make sure that stern drain plugs are
securely tightened before launching the
watercraft.
EJU00459
Engine break-in
The engine break-in period is essential to
allow the various components of the engine
to wear and polish themselves to the correct
operating clearances. This ensures proper
performance and promotes longer compo-
nent life.
CAUTION:
●For the first tankful of operation, pre-
mix a 50:1 mixture of fuel and oil (in
addition to the oil in the oil tank).
●After break-in, use straight gasoline
for normal operation.
1. Launch the watercraft and start the
engine. (See pages 3-15 to 3-17 for
engine starting procedures.)
2. Run the engine at the lowest possible
speed for 5 minutes.