Generic TR 125 Service Manual page 29

If idle speed RPM is unsteady, or idle speed is not smooth when gently raise engine speed, adjust idle speed
adjusting screw again.
Cylinder pressure
Operation when engine is warming.
Disassemble spark plug.
Install roof cylinder pressure gage.
Fully open accelerator; start engine to measure cylinder
pressure.
Compression pressure: 1.1-1.3Mpa/1,400rpm
When compression pressure is too low, check the
following items:
Damage of cylinder head gasket
Damage of piston ring
Piston ring scuffing
Piston and cylinder scuffing.
Check when compression pressure is too high or carbon deposit is too much in combustor or the head of
piston.
Drive Chain Slackness
Service life of drive chain relies on proper lubrication
and adjustment. If not maintained in a proper way,
advanced abrasion will come out in drive chain or chain
wheel. In the harsh using conditions, maintain frequently
is necessary.
Stand vertically the motorcycle on the flat ground and check drive chain slackness
Drive chain slackness: 10-20mm
Adjustment of drive chain:
Adjust drive chain to keep the deflection of chain is 10-20mm per 1000km.
According to users' driving conditions, drive chain likely need to be adjusted often.
Warning:
This advice is the maximum adjustment time gap.
In fact chain should b checked and adjusted every
time before driving. If chain is too loose, accident
caused by chain dropping may happen or serious
damage of engine may be caused.
Measure cylinder pressure
- 24 -
○
,a.