Generally marine propellers like to turn more slowly than marine
engines, so almost all "marine gears" provide both
forward-neutral-reverse and a speed reduction. Exceptions are almost
all very high speed boats.

2:1 is certainly a "normal" reduction ratio, particularly for a
smaller boat.

ZF claims to be the largest manufacturer of marine transmissions in
the world.
see http://zf-marine.com/ for more than you wanted to know about the
subject.

Jim Woodward
www.mvFintry.com



"John Salyer" wrote in message ...
"Common" is the key word!!
Thanks

"Jeff Morris" jeffmo@NoSpam-sv-lokiDOTcom wrote in message
...
In my limited experience, 2:1 is a common reduction ratio. Of course, its
important that
the propeller be sized accordingly.


"John Salyer" wrote in message
...
I'm looking at a boat for sale on the internet and it lists this:
ZF 2:1 Transmission
Is this some big deal? Do they make transmissions with different
ratios?
Is a 2:1 ratio good? I've never seen this before.
Thanks, John