The Seloc manual can make it hard to understand some things at times. As for setting the timing on the motor, the 30 degrees at WOT is when the motor is at or near 5300 RPM and needs to be done in a test tank with a test wheel in place of the prop[. The 24 degrees has to be done when the motor is in a test tank also. The 18 is with the motor at idle with the motor in FWD and in water. On most motors the timing advances as the RPM increases and it is best to check the timing at the idle and the WOT to make sure that the motor is where it should be and not firing the cylinders before those settings. I usually set my motor 1 degree less than what is called for to be sure that the motor dose not predetenate and could cause damage to the motor. JMO
Oldman570