Ok, Let's try this again...
Yes, it is OK to run, with a few caveats.

#1) Be sure you have greased the bowl, and thrust bearings, but then
you should be doing this every time it goes out anyway (easy to forget
that bowl bearing, ever priced a Jacuzzi shaft? 9-Bones+ IF you can
find one. Let's not burn that up by forgetting to grease the bloody
thing!)

2)be sure you have flushed any "road garbage" out of the impeller.
Remove inspection cover, and garden hose it out. The YJ is an axial
flow pump, and not too prone to road rocks eating up the wear ring, but
still a good idea. Anyone using a mixed flow impeller has more of a
problem with "road junk" getting into the intake. This is still a
problem when you first put the boat in the lake too, but the water can
quickly wash the debris away.

3) Engine cooling is drawn off the pump bowl, through a nipple fitting
on the Left side of the suction piece (as you look backwards from the
front) You should see a 3/4" hose coming off it. Get a garden hose
repair set (both the connectors) attach the female end toward the
ENGINE "T" fitting, the male on the pump bowl. I use the heavy-duty
style, that attach with real hose clamps, not the crimp-on wally-world
59 cent ones. To run the engine take the fitting apart, and attach your
garden hose to the engine side, turn on water, and start engine. Works
great!

Be sure to turn the water off when the engine is not running if you
have a thermostat installed (most do not have a thermostat.)

Also works to flush contaminated/salt water from engine.

It is a good idea to consider is to add a pressure regulator to the
line. Especially with Olds engines, the excessive water pressure leaks
past the gaskets and contaminates oil (causes milky looking oil). Car
engines like 14-35 PSI in their cooling systems, not the 100-150 PSI
developed in jet drives.

Hope this helps


Oh, yes, and don't forget to reattach, and tighten the connector before
putting the boat in the water... or you get a big, wet surprise.