Removal; Inspection; Float Height - Yamaha YTZ250S 1986 Service Manual

WARNING
When the drain plug is removed, the fuel
in the float bowl will drain. Do not remove
the plug when the engine is hot. Place a
rag under the carb when removing the
plug to catch the fuel. Remove the plug
in a well-ventilated area, away from any
open flame. Always clean and dry the
machine after completing main jet
changes.
IMPORTANT:
--------------~
The carburetor (with standard settings)
is set for operation at sea level and nor-
mal temperature. Some particular con-
ditions (e.g., high altitude, low winter
temperature, etc) do demand a change
in carburetor settings to maintain per-
formance. Standard carburetor settings
in the above conditions can lead to poor
performance or possible engine
damage. If you use the machine in such
particular conditions, consult your
Yamaha dealer.
Removal
1. Remove the coolant reservoir tank.
2.
Loosen the joint clamp screws and
disconnect the fuel hose.
,
I
1. Fuel hose
3-8
Inspection
1. Examine carburetor body and fuel
passages. If contaminated, wash car-
buretor in petroleum-based solvent. Do
not use caustic carburetor cleaning solu-
tions. Blowout all passages and jets with
compressed air.
2.
Examine condition of floats. If floats are
damaged, they should be replaced.
3.
Inspect inlet float valve and seat for wear
or contamination. Replace these com-
ponents as a set.
1. Valve seat
Float Height
2. Float valve
( ' \
",1 ./
'r
(2)
mY
Hold the carburetor in an upside down posi-
tion . Incline the carburetor at
60
0
-70
0
(so that
the end of the float valve does not hang down
of float weight), and measure the distance from
the mating surface of the float chamber (gasket
removed) to the top of the using a gauge.
Float height:
31.3±1.0 mm (1.23±0.04 in)
Level with carburetor base
Check the float valve and valve seat for
wear before adjustment.
Make the adjustment by bending the tang on
the float arm.