2001-2002 Yamaha 50HP F50Z/T50Z Ouboard 4-stroke engines service manual, Page 23Get this manual
Technical tips Starting control When starting the engine, the timing is set to BTDC until the crankshaft speed maintains 600 rmin for two seconds or longer
S62Y1350
Protrusion for cylinders #1 and #4 Pulser coil Protrusion for cylinders #2 and #3 Pulser coil signal Cylinder identification signal
G) Cylinder identification protrusion
o Starting signal (5 BTDC) for cylinders #1 and
#4 Starting signal (5 BTDC) for cylinders #2 and #3 Rotating direction