2021 YAMAHA GP800R Owners Manual

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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.

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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.

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EJU00544
Inspecting the oil injection
system
Check the oil injection system for leakage,
cracks, or malfunctions. If necessary, have a
Yamaha dealer repair the oil injection sys-
tem.
Check:
●Oil tank for damage, cracks or leakage.
●Oil tank for water or dirt.
●Oil hose and joint for damage or cracks.
●Oil filter for dirt.
●Oil pump for leakage.
Oil tank
Check the oil tank for leakage or water in
the tank. If water is found in the oil injection
system or if the oil tank needs to be cleaned
have a Yamaha dealer service the water-
craft.
Oil filter
Check the oil filter 1 for dirt and clogs. If
the oil filter is clogged, remove it from the oil
tank together with the oil level sender and
clean it.

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j
EJU00546a
Inspecting the steering cable
Check for smooth operation of the handle-
bars and jet thrust nozzle.
Turn the handlebars as far as possible to
the right and left and check that the differ-
ence of distance A and B between the jet
thrust nozzle and the nozzle is within 5 mm.
If steering is stiff or misadjusted, have a
Yamaha dealer service it.Difference of A and B:
Maximum 5 mm (0.20 in)
EJU00550
Inspecting and adjusting the
throttle cable
Check that the throttle cable moves back
to the set position smoothly and that free
play is within specification.
1. Squeeze and release the throttle lever. If
the lever does not return smoothly, have
a Yamaha dealer service it.
2. Adjust free play a by loosening the lock-
nut 1 and turning the adjuster 2.
Throttle lever free play:
4–7 mm (0.16–0.28 in)

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EJU00551
Inspecting the QSTS
mechanism
Check that the shift lock lever moves back
to the lock position smoothly, that the QSTS
selector locks and unlocks properly, and that
the jet thrust nozzle moves up or down.
1. Squeeze and release the shift lock lever.
2. Check that the QSTS selector locks
when the lever is released.
3. Check that the selector turns smoothly
when the lever is squeezed and held in
place.
4. Check that the angle of the jet thrust
nozzle changes when the selector is
shifted from neutral to bow-up or bow-
down.
If the mechanism does not work properly,
have a Yamaha dealer service it.

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EJU00552a
Cleaning and adjusting the
spark plugs
The spark plug is an important engine
component and is easy to inspect. The con-
dition of the spark plug can indicate some-
thing about the condition of the engine. For
example, if the center electrode porcelain is
very white, this could indicate an intake air
leak or carburetion problem in that cylinder.
Do not attempt to diagnose any problems
yourself. Have a Yamaha dealer service the
watercraft.
Remove and inspect the spark plug peri-
odically; heat and deposits will cause the
spark plug to slowly break down and erode.
If electrode erosion becomes excessive, or if
carbon and other deposits are excessive,
replace the spark plug with the specified
plug.
Measure the spark plug gap a with a
wire thickness gauge before installing the
spark plug. Adjust the gap to specification if
necessary.
To reinstall spark plug:
1. Clean the gasket surface.
2. Wipe any dirt from the threads of the
spark plug.
3. Screw the spark plug to the correct
torque. Standard spark plug: BR8ES
Spark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Spark plug torque:
25 N·m (2.5 kgf·m, 18 ft·lb)

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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)

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●Throttle cable (handlebar end)
Pull the throttle lever and remove the seal 1.
Spray a rust inhibitor into the outer cable. Refit
the seal securely.
●Steering cable (handlebar end)
●Steering cable (nozzle end)
●Nozzle pivot shaft
●QSTS cable (nozzle end)
●QSTS cables (pulley end)