I am an auto tech, and just bought a used 28 hp johnson .Upon examining the motor I found that the maximum spark advance set screw was backed off, I have no idea where it was. I have a service manual and went thru the procedures but not having a test wheel like the manual requires I am at a loss. Do you think the boat pointed at a dock with the prop I would be able to set the wot timing to specs? If not, do you have any suggestions to help with my propblem? Also do you think running a prop instead of a test wheel provide the proper rpm to set wot timing? thanks!
Securing the boat to the side of the dock would be a better choice. Nosing into the dock might end up spinning you sideways, dumping you overboard and those are just two scenarios I envision. Leaving the boat secured to the trailer and backing in far enough to run the motor is another safer option (assuming the boat is tied down in front and in back).