Yamaha 13.5A Owner's Manual page 171

Trouble
E. Engine vibrates
excessively.
Possible Cause
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.
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.
5-4
GB
Remedy