Cleveland CycleWerks ACE 250CC, User Manual, Page: 51 / 57

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Abnormal noise
from engine
1
、
Worn out cylinder and
piston
2
、
Worn out needle bearings
in small and big ends of
connecting rod
3
、
Premature ignition
4
、
Excessive carbon deposit
in combustion chamber
5
、
Overheated spark plug
1
、
Replace cylinder body
and piston
2
、
Replace bearing and
relate parts
3
、
Adjust ignition time
4
、
Clean out carbon
deposit
5
、
Replace spark plug
Unstable engine
operation
1
、
Water or dirt in the
carburetor
2
、
Clogged fuel passage
3
、
Leaking crankcase
4
、
Leaking connection
between carburetor and
engine
5
、
Over-­‐rich or over-­‐thin gas
mixture
1
、
Clean the carburetor
2
、
Clean or replace fuel
lines
3
、
Replace seal
4
、
Tighten screw
5
、
Adjust carburetor
Abnor
m
al
e
ng
ine
ope
rat
ion
Excessive heat from
the engine
1
、
Lugging the motor over an
extended period
2
、
Over loaded motor
3
、
Unqualified engine oil
4
、
Slipping clutch
5
、
Chain too tight
6
、
Brakes stuck
1
、
Change gear position
to a lower gear
2
、
Reduce load
3
、
Replace with qualified
engine oil
4
、
Adjust free play or
replace clutch, friction
lining and spring
5
、
Adjust tension
6
、
Adjust brake
clearance