Water Diverters

1nebel0

Chief Petty Officer
Joined
Nov 28, 2005
Messages
512
I have a 1989 v4 90h.p with the port head running very cold. New water pump is pissing great and before I sell the boat and motor want it all perfect... I know Mercury's very well but don't own other Evenrudes so I believe that the port head could have a diverter or clogged issue.. I cannot find pic's or location where the two diverters go in each head. Plan on taking both heads off and putting in new diverters and clean out any debris that might be in the motor...Thanks in advance to anyone that can provide.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Usually a mis-located diverter will result in a hot head, not a cold one. You may have a thermostat stuck open instead. See pic for the diverter. The pictured one to the left is ok, the righmost one is an example of one misplaced diverters.jpg out of place.
 

V153

Lieutenant Commander
Joined
Apr 16, 2011
Messages
1,764
I agree. Sounds like too much flow vs not enough. Check the tstat & poppet valve(s).
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,135
If the stats/pop arent stuck open check those cylinders are running with a drop test
 
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