Engine Lacks Power - Honda CH250 Elite 1986 Service Manual

TROUBLESHOOTING
ENGINE LACKS POWER
Probable cause
1.
Ac,a'All~ra'te
lightly
ENIGII\IE SPEED INCREASES
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NOT
-----I.....
(1) Clogged air cleaner
INCREASE SUFFICIENTLY (2) Restrictedftl,el
(3) Clogged fuel tank breather
(4) Clogged muffler
(5) Faulty
aLlto-byStartl~r
(6) Split carburetor vacuumpisfdl1
diaphragm
CORRECT
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3. Check valve clearance
CORRECT
•
4. Test cylinder compression
NOT CLOGGED
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6, Remove spark plug
FOULED OR DISCOLORED - - ' - - - -........... (1) Plug not serviced frequently
enough
(2) Use of plug with improper heat
range
TOO LOW - - - - - - - - - -........... (1) Improper valve and seat contact
(2) Worn cylinder piston rings
(3) Leaking cylinder head gasket
(4) Flaws in cylinder head
(5) Improper valve timing
INCORRECT OR CONTAMINATED_
(1)
Oil level
too
high
(2) Oil level too low
(3) Oil not changed
CLOGGED - - - - - - - - - -........ Carburetor not serviced frequently
enough
VALVE TRAIN NOT
~-----~
(1)
Clogged oil pipe
LUBRICATED PROPERLY (2) Faulty oil pump
INCORRECT - - - - - - - - - _ .. (1) Improper valve clearance
adjustment
(2) Worn valve seat
INCORRECT - - - - - - - - -..... (1) Faulty COl unit
(2) Faulty pulse generator
NOT FOULED OR DISCOLORED
~
7. Check oil condition
CORRECT AND NOT
CONTAMINATED
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8. Remove cylinder oil
pipe bolt
NORMAL
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5. Check ~::lI'hulrAt'''lr for clogging
2. Check
9. overheating
NOT OVERHEATING
OVERHEATING - - - - - - - -........... (1) Insufficient coolant
(21 Thermostat stuck closed
(3) Worn cylinder piston rings
(4) Lean mixture
(5) Fuel contaminated
(6) Excessive carbon build-up in
combustion chamber
(7) Faulty CDI unit
10. or run at
ENGINE DOES NOT KNOCK
ENGINE KNOCKS - - - - - - - . . . . ,.....
(1)
Excessive carbon build-up in
combustion chamber
(2) Use of poor quality fuel
(3) Clutch slipping
(4) Lean mixture
(5) Faulty COl unit
19..2