2007 YAMAHA YZ250LC light

5-22
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
9Brake hose holder 1
9Bolt (brake hose holder) 2
3. Install:
9Brake hose holder 1
9Nut (brake hose holder) 2
NOTE:
Align the top aof the brake hose holder with the
paint bof the brake hose.
10 Nm (1.0 m•kg, 7.2 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
4. Install:
9Pin 1
9Plain washer 2
9Cotter pin 3
NOTE:
After installing, check the brake pedal height.
Refer to “REAR BRAKE ADJUSTMENT” section
in the CHAPTER 3.
EC5A5911
Front brake hose
1. Install:
9Copper washer 1
9Brake hose 2
9Union bolt 3
w
Always use new copper washers.
cC
Install the brake hose so that its pipe por-
tion a a
directs as shown and lightly touch-
es the projection b b
on the caliper.
30 Nm (3.0 m•kg, 22 ft•lb)
1P8-9-32-5a 4/10/06 4:40 PM Page 44

5-23
CHASFRONT BRAKE AND REAR BRAKE
4. Pass the brake hose through the cable
guide 1.
5. Install:
9Copper washer 1
9Brake hose 2
9Union bolt 3
w
Always use new copper washers.
cC
Install the brake hose so that its pipe por-
tion a a
directs as shown and lightly touch-
es the projection b b
on the master cylinder.
30 Nm (3.0 m•kg, 22 ft•lb)
EC5A5502
Rear brake hose
1. Install:
9Copper washer 1
9Brake hose 2
9Union bolt 3
w
Always use new copper washers.
cC
Install the brake hose so that its pipe por-
tion a a
directs as shown and lightly touch-
es the projection b b
on the caliper.
30 Nm (3.0 m•kg, 22 ft•lb)
1P8-9-32-5a 4/10/06 4:40 PM Page 46

7-9
SETTINGTUN
EC71D021
Examples of carburetor setting depending on symptom
Symptom Setting Checking
At full throttle Increase main jet calibration No. Discoloration of spark plug 
Hard breathing (Gradually) If tan color, it is in good condition.
Shearing noise If can not be normalized:
Whitish spark plug Clogged float valve seat
Clogged fuel hose
Lean mixture Clogged fuel cock
At full-throttle Decrease main jet calibration No. Discoloration of spark plug 
Stop of speed pick-up (Gradually) If tan color, it is in good condition.
Slow speed pick-up *In case of racing slight enrichment If not effect:
Slow response of mixture reduces engine trouble. Clogged air cleaner
Sooty spark plug Fuel overflow from carburetor
Rich mixture
Lean mixture Lower jet needle clip position.
(1 groove down)
Rich mixture Raise jet needle clip position.
(1 groove up)
1/4~3/4 throttle Lower jet needle clip position.
Hard breathing (1 groove down)
Lack of speed
1/4~1/2 throttle Raise jet needle clip position. Clip position indicates the position of
Slow speed pick-up (1 groove up) jet needle groove, to which the clip is
White smoke fitted. The position is numbered from
Poor acceleration the top.
Leaner
(Standard)
Richer


EC71C030
Road condition and examples of carburetor setting
åFor USA and CDN
∫For EUROPE
çFor AUS, NZ and ZA
NOTE:
Optimum pilot air screw setting can be abtained by adding the ex-factory number of the same screw
back-out turns to any required value provided in the chart.
For example, if the ex-factory number is “1”, add “1” to the value chosen in the chart.
Conditions General condition Sandy condition
Under 10°C 15~25°C Over 25°C Under 10°C 15~25°C Over 25°C
(50°F) (59~77°F) (77°F) (50°F) (59~77°F) (77°F)
Parts (Winter)(Spring, Autumn)(Summer) (Winter)(Spring, Autumn)(Summer)
Main jetå, ç#178 #178 #178 #180 #178 #178
∫#180 #178 #178 #182 #180 #178
Jet needleå, çN3CW-3 N3EW-2 N3EJ-2 N3CW-3 N3CW-3 N3CW-3
∫N3EW-3 N3CW-3 N3EW-2 N3CW-4 N3EW-3 N3EW-3
Pilot jet#50 #50 #50 #52 #52 #52
Pilot air å, ç-1/4 Zero Zero Zero Zero +1/4
screw ∫-1/4 Zero Zero -1/4 Zero +1/4
Power jet #50 #50 #50 #50 #50 #50
1P8-9-32-7 4/28/06 3:47 PM Page 18

7-11
SETTINGTUN
EC71M010
Change of the heat range of spark plugs
Judging from the discoloration of spark plugs, if
they are found improper, it can be corrected by
the following two methods; changing carburetor
settings and changing the heat range of spark
plug.
9In principle, it is advisable to first use spark
plugs of standard heat range, and judging from
the discoloration of spark plugs, adjust carbure-
tor settings.
9If the calibration No. of the main jet must be
changed by ±15, it is advisable to change the
heat range of spark plugs and newly select the
proper main jet.
NOTE:
9When checking the discoloration of spark
plugs, be sure to stop the engine immediately
after a run and check.
9Avoid racing.
9When changing the heat range of spark plugs,
never attempt to change it more than ±1 rank.
9When using a spark plug other than standard,
check its heat range against the standard and
check that it is a resistance type.
9Note that even if the discoloration seems prop-
er, it may slightly vary with the spark plug
maker and oil in use.
Standard spark plugBR8EG/NGK(resistance type)
1P8-9-32-7 4/28/06 3:47 PM Page 26