Yamaha SRX440 1980 Service Manual page 36

1980 SRX440D
Spare pilot jet:
#90, #80
1. Pilot jet
2. Turn the pilot screw in and out 1/4 turn
or less each time, and set it in a position
where the engine idles faster.
3. Follow step C in the preceding par-
agraph.
6. Main circuit tuning
No adjustment is normally required, but
adjustment is sometimes necessary de-
pending on temperatures and/or al-
titude. (Refer to Jet setting chart.)
Temperature
Altitude
-30°C
(-22°FI
-20°C
(-4°F)
-10°C
(14°FI
aOc
(32
OF)
10°C
150°F)
Sealevel
Up
to 1000 m
13000 It)
Up
to 2000
m
16000 It)
Up
to 3000
m
110000 It I
MJ #260
PJ #85
MJ #240
PJ#85
MJ #210
PJ#95
MJ #180
PJ#105
- M J #
2501~~­
PJ#85
- M J # 2 3 0 - - -
PJ #85
-MJ#200-~­
PJ#95
-MJ#170-~­
PJ #105
MJ #240
PJ
#
85
MJ #220
PJ #85
MJ #190
PJ #95
MJ #160
PJ #1 05
a. Run the engine at high speeds, and
make sure the engine operates smooth-
ly.
b. Check both spark plugs and, depending
on the discoloration of each spark plug,
the main jet should be adjusted on the
basis of the following table. (Refer to
spark plug color samples.)
Standard main jet:
#260
Spare main jet:
#270,#250,#240,#230
Spark plug color
No.1
Good (Carburetor is tuned properly.)
Bad (Mixture is too rich.)
NO.2
Replace main jet with one-step
smaller one.
Bad (Mixture is too lean.)
No.3
Replace main jet with one-step
larger one.
Bad (Due to too lean
a mixture.
piston
is holed or seized.]
No.4
Replace the piston and spark plug.
Tune the carburetor again, starting
with low-seed tuning.
Bad (Due to too lean a mixture. the
engine knocks.)
Check the piston for holes or seizure.
No.5
Check the cooling system. gasoline
octane rating and ignition timing. After
replacing the spark plug. tune the
carburetor again. starting with
low-speed tuning.
4-4