Poor Performance At Low And Idle Speeds/At High Speed - Honda Nighthawk CB 750 1991 Service Manual

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Troubleshooting
Possible Cause
12.
Check for engine overheating
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Overheating
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Excessive carbon build-up in com-
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bustion chamber
Not Overheating Use of poor quality fuel
1
Clutch slipping
Lean fuel mixture
Wrong type of fuel
13. Accelerate or run at high speed- Engine Knocks
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Worn piston and cylinder
4
Wrong type of fuel
Engine Does Not Knock
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Excessive carbon build-up in com-
bustion chamber
Ignition timing too advanced
(Faulty ignition control module)
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Lean fuel mixture
Poor Performance At Low And Idle Speeds
Possible Cause
1. Check ignition timing and l ncorrect
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Tappet oil holes clogged
hydraulic tappet condition Tappet damaged
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Improper ignition timing
Cor~ect (Faulty ignition control module)
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2.
Check carburetor pilot screw Incorrect
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See Fuel System Section
adjustment
I
I
Correct
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3.
Check for leaking intake pipe
Leaking
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No Leak
t
4.
Perform spark test Weak or Intermittent S p a r k - .
4
Good Spark
Poor Performance At High Speed
Loose insulator clamps
Damaged insulator
Faulty, carbon or wet fouled spark
plug
Faulty ignition control module
Faulty ignition coil
Broken or shorted spark plug wires
Faulty engine stop switch
Faulty ignition pulse generator
Fautly ignition switch
Loose or disconnected ignition
system wires
Possible Cause
1. Check ignition timing and Incorrect
-.
Damaged hydraulic tappet
hydraulic tappet conditon
Faulty ignition control module
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Faulty ignition pulse generator
Correct
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2. Disconnect fuel tube at Fuel Flow Restricted
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Clogged fuel line
carburetor Clogged fuel tank breather
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Clogged fuel strainer
Fuel Flows Freely
J
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18-3