Gene Kearns wrote:


It is pretty simple, really.

The water pump that is trying to pump water from the bottom of the
engine (the foot) to the top to the water jacket.

During flushing(using the port provided for this), the water flow is
not in the same direction as one (or the pump) would expect if the
engine were running.

Thus, it is a *really* bad idea to run the engine without water
available to the bottom of the engine to be pumped *up.*

My Suzukis have this feature and the manual says not to run while
using the flushing port. When I moved my boat down to a dry storage
almost within sight of the ramp, I became concerned that throwing cold
tap water into the flushing port might shock cool the engine. I called
Suzuki engineering and they said *that* wasn't a problem, but they
made a POINT to make sure that I knew that I could NOT run the engine
while using the manufacturer's flushing port.

Of course, your manufacturer's maintenance manual trumps anything you
read here.... what does it say?


My last Merc and Yamaha and my current Yamaha have a hose mounting at
the powerhead for flushing. The flushing is done with the engine shut
off. I don't use the fresh water hose at full pressure. I usually hook
up the flush and empty my gear out of the boat while the motor is
rinsing itself out. Maybe 15-20 minutes on the fresh water. When I wash
the boat out with soapy water, I also wash off the engine. When the boat
is pretty dry, I put the canvas cover on it. I probably spend about an
hour cleaning out the boat after use.

Putting the cover on is a real pain in the ass, but it ensures the boat
is clean when I use it again.