Moderated Discussion Areas
ContinuousWave: Whaler Performance
Prop Questions for Twins
|Author||Topic: Prop Questions for Twins|
posted 07-22-2000 06:21 PM ET (US)
Is there any performance difference regarding counter-rotating versus similar-rotating props? Does the lower unit control the direction of rotation or does the engine rotate differently? The reason I am asking is I might be able to make a deal on a counter-rotating motor like mine with a blown powerhead. My twins are similar-rotating 1989 Yamaha 70 hp.
posted 07-22-2000 06:28 PM ET (US)
My props are stamped '17-K' Anyone know what it means? I suspect they are stock Yamaha props. They are stainless steel but they do rust slighty.
posted 07-22-2000 09:46 PM ET (US)
The 17 indicates 17" pitch,the K indicates Steel (black painted)as in accessory catalog
posted 07-23-2000 12:12 PM ET (US)
Tom: Many people don't realize that stainless steel means "stain" "less" (than regular steel. It can exhibit surface rust, but this can usually be polished off the surface.
Regarding counter rotation, the lower unit gear case is where it happens, but different shift controls are also needed. Mercury, for example, makes two twin engine control boxes - one for twin regular rotation, and one for twin counter rotation. I have a Whaler with both setups, and the counter rotation is far superior, eliminating the steering and port lean characterists of
Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.