The ABCs of Carburetion
UM-900 (1959)
Page 15 of 19
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TROUBLE SHOOTING TIPS Continued
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FLOAT SYSTEM
(Hooding, rough
idle, surge)
1.
Check seat for tightness in
casting.
2. Is the
needle smooth both on the point and the top?
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PART THROTTLE SYSTEM
(poor economy, surge)
1. Check size and
approach angle of metering jets.
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2. Are the jets and
fuel passages free of dirt or obstruction?
POWER SYSTEM
(surge, low top speed, hesitation)
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3. Does the
needle valve seat properly to prevent flooding?
4. Check float adjustment.
IDLE SYSTEM
(rough idle,
stalling)
1.
Check float adjustment, engine
idle speed adjustment.
2. Check for vacuum leaks.
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1. Are the vacuum
channels and power restriction free of carbon, dirt, or obstruction?
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3. Are the idle channels and throttle bore
free of carbon and dirt?
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2. Is the power piston worn or damaged?
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4. Are the idle needles free of burrs?
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3. Is the actuating spring distorted?
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15
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