Most of my jet pump experience is with KaMeWa units behind 1500+hp Diesels
or 3500+hp gas turbines.
"Netsock" wrote in message
...
Most of the more advanced pumps have buckets which shoot down and to
the
sides(along with forwards), when you turn the nozzel, the side forces
get
unbalanced and spin the boat. Often with larger jets the pumps are also
clutched and with multi units they have an option to independently
control
the steering per pump.
All my experience has been with big block Berkeley and Dominator pumps.
Those keep a "neutral" by equally maintaining rear, and forward thrust.
A properly set up Berk or Dom will not move in "neutral" no matter what
way
the nozzle is pointed.
Oh well...live and learn! 
--
-Netsock
"It's just about going fast...that's all..."
http://home.insight.rr.com/cgreen/