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1. |
Remove
carburetor. |
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2. |
Remove
bowl plug and main jet. |
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3. |
Install
Master Tune main jet. Tighten properly. |
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4. |
Install
Master Tune plug. Tighten properly. |
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5. |
Lubricate
"O" ring with oil and install needle. |
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6. |
Make sure the plug fits the gearbox properly (goes all the way in). Tighten the 2.5 mm Allen bolt and compression washer provided with the clamp. |
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To verify
that the needle rotates properly, with the carburetor in your
hands, turn the knob clockwise to the closed position. Looking
at the bottom of the carburetor rotate the knob counterclockwise.
It should rotate 14 or 15 turns, which represents 3-¼
to 3-½ turns in the needle.
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7. |
Install
the carburetor. |
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8. |
The flexible
shaft should be towards the right side (chain side), although
some carburetors are not as close to the cases as others and
will allow the flex shaft to be at an angle towards the air
filter, thus eliminating a sharp turn to avoid hitting the chain. |
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9. |
Secure
the flexible shaft in the lower portion with tie wraps to prevent
it from rotating, and position the knob near the spark plug
in a position that is comfortable to reach while driving. Secure
here with two tie wraps. |
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Before
going to the track, close the needle all the way (clockwise)
and then open (counterclockwise) approximately 7 turns. This
will be the equivalent in jet size to a 200 to 210 jet (rather
rich) in a Dellorto or Keihin carburetor.
Start
your motor. After warming it up, accelerate gently to confirm
you are rich. If you are not, turn the knob counterclockwise
to open the needle. If it does not start the bowl may be dry.
Also try opening the needle more (it may be too lean) or close
it more (it may be too rich).
If
you follow the instructions properly, the first time in the
track
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you
should be rich. Start closing the needle while watching your
EGT. It must start going up in temperature and the response of
the motor will improve. Close it until you feel the motor
going lean, and your EGT temperature drops, go immediately
back-up and that is your optimum carburetion. Some people will
like to run 100°F (38°C) to 200°F (76°C) richer than peak,
some will drive with the EGT at peak all the time. Now with
MasterTune you have a choice.
When
you go back to the track two or three hours later and the
weather is different, you know your EGT peak temperature,
so you can adjust to find it.
In your
parade lap, when you are not going flat out, lean it a bit
to prevent fouling the plug and maintain a clean cylinder
head. When you are coming to the last corner, before the green
flag, richen it up to the proper setting to start the race.
When you are in the lead by a mile, there is no need to beat
your equipment, so richen it up to run a more conservative
pace. When you are chasing the leader, adjust to get peak
EGT readings to obtain your optimum power.
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Note:
There is a shim washer with the jet. Do not use unless it
is necessary. The way to tell is if you adjust the knob
all the way in and you are still rich, that means that the
bottom of the jet is too far away from the needle, so the
shim will bring it down closer.
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