I currently just run a hose through a shut-off valve and turn down the water to get the temp in the ball park, when I'm running at speed my temp wants to dip in the 120's, but when I idle its around 180+.. So, I'm thinking about installing a thermostat in conjunction w/ a bypass kit to get it right in the 160 range.   Here's a discussion I pulled off www.performancejet.com some time ago, but the site is now down (was able to google it and find the article in the cache)..  Do you think what is explained below will work?


" Now, for you Ford people that can't use the bypass thermostat kit because it won't fit your manifold, this is what I do, and it works just fine.  I take off the stock thermostat housing and mill out the divider on the inside just enough to install a 160 degree marine thermostat.  I drill two 3/16" holes on each side of the thermostat body so that water will still exit the engine when closed.  Re-install the thermostat and install a pressure relief kit in front of the engine (off of the jet).  Set up your water lines as previously discussed.  NOTE*  You must use the pressure relief kit or you will have too much water pressure in the engine when the thermostat is closed.  In my opinion, these are the basic solutions for most engine cooling problems for the average jet boat.  PERFORMANCE JET can set you up with everything that you need, or you do it yourself, but remember, don't skimp.  Buy good parts and do the job right the first time.  Remember your jet boat is supposed to be a pleasure boat.  So keep it that way. "