Honda CM400A - Engine Power and Performance Issues

HONDA
TROUBLESHOOTING CB400T
-
ENGINE LACKS POWER
Possible Cause
1. Raise wheels and spin them WHEELS DO NOT
- (1) Brake dragging
by hand.
SPIN FREELY (2) Worn or damaged wheel bearing
(3) Wheel bearing dry
WHEELS
SPIN FREELY (4) Drive chain too tight
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t
2. Check tire pressure. PRESSURE LOW L (1) Punctured tire
12) Faulty tire valve
PRESSURE NORMAL
3. Accelerate rapidly from
ENIGNE SPEED UNCHANGED - (1) Clutch slipping
low to second. WHEN CLUTCH RELEASED (2) Worn clutch disc
(3) Clutch disc warped
ENGINE SLOWS WHEN
CLUTCHRELEASED
4. Accelerate lightly
SPEED INCREASES
5. check ignition timing
NO SIGNIFICANT
- (1) Carburetor choke closed
INCREASE IN ENGINE
(21 Clogged air cleaner
SPEED
(3) Restricted fuel flow
(4) Clogged fuel tank breather cap hole
(5) Clogged muffler
TIMING INCORRECT
- (1) Faulty C.D.I. unit
12) Faulty A.C. generator
TIMING
CORRECT
t
6. Check valve clearance CLEARANCE INCORRECT - (1) Improper adjustment
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(2) Worn valve seat
t
7. Test cylinder compression COMPRESSION LOW - (1 I Valve stuck open
(2) Worn cylinder and piston
(3) Blown cylinder head gasket
COMPRESSION NORMAL (4) Valve timing incorrect
8. Check carbureto~
for clogging
CARBURETOR CLOGGED
- (1) Carburetor not serviced frequently
enough
CARBURETOR CLEAN
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Date of Issue: Sepremoer. 1977
O HOhDA MOTOR CO.. LTD.