Yamaha Outboards 3P Service Manual, Page 78Get this manual
? ENGINE IS HARD TO START OR WILL NOT START
Is the piston ring damaged or worn?
Replace
Are the oil-seals in good condition?
Replace
RE-CHECK YES Does the stop-switch remain closed?
Replace
Is each connection loose?
Tighten
Is the spark-plug cracked?
Replace
Is the spark-plug type correct?} YES