Yamaha Z250D Owner's Manual page 206

Trouble
E. Engine power loss.
F. Engine vibrates
excessively.
5-3
Possible Cause
13. Poor connections or damaged ignition
wiring.
14. Failed ignition parts.
15. Specified engine oil not used.
16. Thermostat faulty or clogged.
17. Fuel pump damaged.
18. Fuel joint connection incorrect.
19. Heat range of spark plug incorrect.
20. High pressure fuel pump drive belt
broken.
21. Engine not responding properly to shift
lever position.
1. Propeller damaged.
2. Propeller shaft damaged.
3. Weeds or other foreign matter tangled
on propeller.
4. Motor mounting bolt loose.
5. Steering pivot loose or damaged.
Remedy
13. Check wires for wear or breaks.
Tighten all loose connections.
Replace worn or broken wires.
14. Have serviced by a Yamaha dealer.
15. Check and replace oil with specified
type.
16. Have serviced by a Yamaha dealer.
17. Have serviced by a Yamaha dealer.
18. Connect correctly.
19. Inspect spark plug and replace it
with recommended type.
20. Have serviced by a Yamaha dealer.
21. Have serviced by a Yamaha dealer.
1. Have propeller repaired or replaced.
2. Have serviced by a Yamaha dealer.
3. Remove and clean propeller.
4. Tighten bolt.
5. Tighten or have serviced by a
Yamaha dealer.
E