Question on counter rotation

[tmitchell5188]

OK, this might sound like a simple dumb question, but what makes a counter rotation, couter rotation? I know the prop turns in the other direction, but is it the lower unit that the extra gear is in or is it in the power head?

 

[seahorse5]

Re: Question on counter rotation

The gearcase has a different internal design than a standard rotation one. The gear in the front is normally the forward gear but becomes the reverse gear in a CCW gearcase. Merc also reverses the shift cable direction in the control box, but Evinrude, Johnson, and Yamaha do not have to.

 

[Frank Acampora]

Re: Question on counter rotation

Are you SURE about that? Things ain't always as simple as they seem. Making the reverse gear forward puts all the prop shaft thrust load on the formerly forward gear, which is now turning opposite the prop shaft--very poor engineering.

 

[pac city]

Re: Question on counter rotation

i assumed that the eng's ran backward's . and props are counter rotating.

 

[Dhadley]

Re: Question on counter rotation

Some of the early OMC (Second Effort) outboards actually ran backwards to create an reverse rotation lower unit. The starter, some ignition parts, linkages, driveshaft and even the water pump was different. Kinda complicated really. It's much simpler to make right hand rotation and left hand rotation gearcases. Either gearcase can run on a standard powerhead, very simple to switch lowers and make conversions. They all run common parts like ignition, starters and water pumps.

The gears in the lowers are not the same between the standard and counter cases. When the rear gear becomes the forward gear it is supported differently and made differently (stronger than a rear gear that's a reverse gear).

There are some outdrives that either the front gear or the rear gear can be the forward gear. IE - that gearcase can be a standard or a counter gearcase simply by switching the way it's shifted. At some point, perhaps in the near future, you'll see an outboard gearcase that can be run in either direction.