2017 YAMAHA YFM90 Owners Manual

Page 89 of 130

YAMAHA YFM90 2017  Owners Manual 8-7
8
15*Steering system • Check operation and repair or replace if dam-
aged.
• Check toe-in and adjust if necessary. √√√√√
16 Engine oil • Change.
• Check ATV for oil leakage, and

Page 90 of 130

YAMAHA YFM90 2017  Owners Manual 8-8
8
EBU23062TIPSome maintenance items need more frequent service if you are riding in unusually wet, dusty, sandy or
muddy areas, or at full-throttle. UBD361E0.book  Page 8  Monday, January 25, 2016

Page 91 of 130

YAMAHA YFM90 2017  Owners Manual 8-9
8
EBU23214Checking the spark plugThe spark plug is an important engine component,
which is easy to check. Since heat and deposits
will cause any spark plug to slowly erode, the
spark plug should b

Page 92 of 130

YAMAHA YFM90 2017  Owners Manual 8-10
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TIPIf the spark plug shows a distinctly different color,
the engine could be operating improperly. Do not
attempt to diagnose such problems yourself. In-
stead, have a Yamaha dealer check the A

Page 93 of 130

YAMAHA YFM90 2017  Owners Manual 8-11
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TIPIf a torque wrench is not available when installing
the spark plug, a good estimate of the correct
torque is 1/4–1/2 turn past finger tight. However,
the spark plug should be tightened to

Page 94 of 130

YAMAHA YFM90 2017  Owners Manual 8-12
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TIPThe engine oil should be between the minimum
and maximum level marks. 5. If the engine oil is at or below the minimumlevel mark, add sufficient oil of the recom-
mended type to raise it to t

Page 95 of 130

YAMAHA YFM90 2017  Owners Manual 8-13
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5. Clean the oil strainer with solvent.
6. Apply a thin coat of clean engine oil to a new
O-ring.
7. Install the oil strainer, the compression spring, the new O-ring and the engine oil
drain bo

Page 96 of 130

YAMAHA YFM90 2017  Owners Manual 8-14
89. Start the engine, and then let it idle for several
minutes while checking it for oil leakage. If oil
is leaking, immediately turn the engine off and
check for the cause.
10. Turn the engine o