Answer

Mercury V-6 outboards do not show water out the tall tale hole until the thermostats open or the throttle is raised while running on a hose with flush attachment, but water should be coming out thru the prop if it is pumping. Also small critters like to build a mud nest inside the water pump indicater hose and fitting in the lower cowling, this can be cleaned out with a stiff wire or compressed air.

That being said, my advice would be to replace the waterpump impeller anyway, it may be dry rotted, or the vanes set in a curved position and even if it is working now it may come apart at higher engine rpms.

Better safe than sorry, since boat and motor sales have been slow in the past few years, Mercury Marine has warned us not to send motors out to customers if they have been setting on our lot for 2 to 3 years unused without installing a new impeller just because of the issues I mentioned. So if your motor has not been run in 3 years it would be best to replace the impeller.

Edited by Larry B. on 6/17/2009 at 2:04 AM

Expert:	Larry B.
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Answered:	6/17/2009

Marine Mechanic

Mercury/ Mercruiser Certified/Verado/DTS Yamaha Two and Fourstroke Certified 26 years experience