How to tell dock buster prop rotation?

gwukena

Petty Officer 2nd Class
Joined
Apr 8, 2010
Messages
167
Re: How to tell dock buster prop rotation?

No electronics on the merc, remember mercury's system was used 50 years ago. For reverse, engine had to be stopped, starter would spin flywheel oppostie direction and engine would run ccw for reverse. Rotax added electronics to skip the step of having to stop the engine, and physically crank the engine backwards.
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: How to tell dock buster prop rotation?

No electronics on the merc, remember mercury's system was used 50 years ago. For reverse, engine had to be stopped, starter would spin flywheel oppostie direction and engine would run ccw for reverse. Rotax added electronics to skip the step of having to stop the engine, and physically crank the engine backwards.

When the inexperienced merc pilot didn't wait for the motor to stop and just yanked the control back, 'thinking' this should be Reverse, it wasn't.....it was still running Forward.

And approaching the dock and not slowing down, yanks the throttle farther open (still thinking this is SUPPOSED to be in Reverse!) and the boat just speeds up!!!!

Hence the handle "Dock Crasher"
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: How to tell dock buster prop rotation?

Fortunately, Mercury quickly discovered how to build a full shift lower unit, to hold up to those big old sixes. Mercury built a helluva fine motor in the old days, but they were behind OMC and Scott Attwater when it came to F-N-R lower units. In 1957, when the Mark 75 came out, they knew that they're full shift wasn't quite ready to put under an inline 6, but in 1960 with the first year of the Merc models, things got a lot better. ;)
 
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