Dinli DL-702 2008, Service Manual

Page: 279 / 306

【
10-4
】
APPENDIX
Poor Running at Low Speed
1. Spark weak
● Spark plug dirty, broken, or maladjusted.
● Spark plug cap or Spark plug cable trouble.
● Spark plug cap shorted or not in good contact.
● Spark plug incorrect.
● CDI unit trouble.
● Pickup coil trouble.
● Ignition coil trouble.
2. Fuel/air mixture incorrect
● Pilot screw and/or idle adjusting screw maladjusted.
● Pilot jet, or air passage clogged.
● Air cleaner clogged, poorly sealed, or missing.
● Fuel level too high or too low.
● Fuel tank air vent obstructed.
● Carburetor holder loose.
● Air cleaner duct loose.
3. Compression low
● Spark plug loose.
● Cylinder head not sufficiently tightened down.
● Loss of valve clearance.
● Cylinder, piston worn.
● Piston ring bad (worn, weak, broken, or sticking).
● Piston ring/groove clearance excessive.
● Cylinder head gasket damaged.
● Cylinder head distorted.
● Valve spring broken or weak.
● Valve not seating properly (valve bent, worn, or
carbon accumulation on the seating surface).
4. Other
● Carburetor vacuum piston doesn’t slide smoothly.
● Engine oil viscosity too high.
● CDI unit trouble.