Engine Lacks Power - Honda 1985 CBX750F Workshop Manual

~HOND.A
~
CBX750F
TROUBLESHOOTING
~
ENGINE LACKS POWER
POSSIBLE CAUSE
WHEELS DO NOT SPIN
FREELY----.,~
1. Raise wheels off ground and
.(1)
Brake dragging
spin by hand
WHEEL SPINS FREELY
!
2. Check tire pressure
PRESSURE NORMAL
3.
+
Accelerate rapidly from low to second
ENGINE SPEED LOWEREDWHEN
CLUTCH IS RELEASED
+
4. Accelerate lightly
ENGINE SPEED INCREASES
1
5.
Check ignition timing
CORRECT
t
6. Test cylinder compression
-
NORMAL
1
7. Check carburetor for clogging
NOT CLOGGED
8. Remove spark plug
•
NOT FOULED OR DISCOLORED
~
9. Check oil level and condition
CORRECT
+
10.
Remove cylinder head cover and
inspect lubrication
VALVE TRAIN LUBRICATED
PROPERLY
~
11. Check for engine overheating
NOT OVERHEATING
! .
12.
Accelerate or run at high speed
ENGINE DOES NOT KNOCK
(2)
(3)
(4)
(5)
PRESSURE L O W - - - - - - -• • (1)
(2)
ENGINE SPEED CHANGED-----. • (1)
WHEN CLUTCH IS RELEASED (2)
(3)
ENGINE SPEED DOES N O T - - -•
• (1)
INCREASED
(2)
(3)
(4)
(5)
• (1)
INCORRECT
----------.,~
(2)
TOO LOW - - - - - - - - - -
• (1)
(2)
(3)
(4)
(5)
CLOGGED - - - - - - - - -
II
(1)
FOULED OR DISCOLORED - - -....... (1)
(2)
INCORRECT----------.
(1)
Oil level too high
Worn or damaged wheel bearing
Wheel bearing needs lubrication
Drive chain too tight
Rear axle nut excessively tight
Punctured tire
Faulty tire valve
Clutch slipping
Worn clutch disc/plate
Warped clutch disc/plate
Carburetor choke closed
Clogged air cleaner
Restricted fuel flow
Clogged fuel tank vent hole
Clogged muffler
Faulty spark unit
Faulty pulse generator
Valve stuck open
Worn cylinder and 'piston rings
Leaking head gasket
Improper valve timing
Excessive camshaft runout
Carburetor not serviced frequent­
lyenough
Plugs not serviced frequently
enough
Spark plug with incorrect heat
range
(2)
(3)
VALVE TRAIN N O T - - - - - -..... (1)
LUBR ICATED PROPERLY (2)
OVERHEATING - - - - - - - - - . . (1)
(2)
(3)
ENGINE KNOCKS - - - - - - -... (1)
(2)
(3)
(4)
Oil level too low
Contaminated oil
Clogged oil passage
Clogged oil control orifice
Excessive carbon build-up in
combustion chamber
Use of poor quality fuel
Clutch slipping
Worn piston and cylinder
Wrong type of fuel
Excessive carbon build-up in
combustion chamber
Ignition timing too advanced
(Faulty spark unit or pulse gen­
erator)
21-2