Air Filter - Yamaha YTZ250S 1986 Service Manual

4. Turn the pilot air screw in or out in
1/8-turn increments to achieve the
highest rpm with just the pilot screw.
5. Once again, turn the throttle stop screw
to attain the desired idle rpm, and tighten
the locknut.
The throttle response off idle should be crisp
and clean, without any hesitation. If the
engine is completely warmed up and
hesitates off idle, turn the pilot air screw in
or out in
1/8-turn
increments until the pro-
blem is eliminated.
Air Filter
Proper air filter maintenance is the biggest key
to preventing premature engine wear and
damage. All elements of the air filter system
should be maintained after every moto; engine
life will be prolonged and power output will
remain consistent.
Never run the engine without the air filter
element in place; this would allow dirt and
dust to enter the engine and cause rapid
wear and possible engine damage. In ad-
dition, carburetor jetting would be signi-
ficantly affected, with subsequent poor
performance and possible overheating.
2-9
1. Remove the seat and upper cover.
2. Remove the air filter box cover and air
filter element.
3. Separate the element from the filter
cage.
4. Wash element gently but thoroughly in
solvent, squeeze the solvent out of the
elements, and allow the element to dry.
WARNING:
Never use low flash point solvents such as
gasoline to clean the air filter element.
Such solvent may lead to a fire or explo-
sion.
5. Pour a small quantity of foam-air-filter oil
or motor oil on the element and work it
thoroughly into the foam. Squeeze out
the excess oil.
Do not twist the filter element when
squeezing the filter element.
6. Reinstall the element on the filter cage,
and coat the sealing edge of the element
assembly with light grease to provide an
airtight seal.