If that's the plan, just put a big e.g. plastic garbage pail under the
outdrive and fill it up with water to protect the impeller. My opinion, the
engine thermostat won't even be opening so except for exhaust/riser cooling
water, very little water if any will actually be input to the engine cooling
system from the pail ... and the water coming out the exhaust will go back
into the pail ... 15-20 seconds, no problem. And starting up like that a
coupla times between outings, no problem ... but why bother?

"IDT 512" wrote in message
om...
"Edward Quillian" wrote in message
...
engine will overheat within about 5 minutes. Bigger problem is you will
destroy the rubber impeller on the water pump.
"IDT 512" wrote in message
om...
how long can i run the engine safely without cooling water? engine is
a
Merc 3.0L.

5 minutes??? i was thinking closer to like 15-20 seconds! I want to
start it up in the garage every once in a while and was wondering if i
can run without the flush kit to avoid getting the garage floor all
wet, otherwise id have to pull it out to the street each and every
time.