On Fri, 11 Sep 2009 14:04:00 -0700 (PDT), fzbuilder
wrote:

Ok here is were I am at.
Took hose from raw water pump and un-hooked it from the thermostat
housing. Started it up and am getting good water shooting out. Took
out the thermostat. Filled the engine with water and flushed it a few
times with a shop vac. Very rusty water. Put housing back on without
thermostat and still no flow out the outdrive. Pulled one of the
risers and they are super clean. I just replaced them 3 years ago, but
have been working on this boat most of that time. I would say it has
to be the water pump at this point. Yes?

That's one of the few things common to both halves of the engine
downstream of the thermostat.