72 mercury cooling issue

DuckCowboy

Recruit
Joined
Nov 26, 2009
Messages
3
I have 72 mercury 4hp motor. Just purchased. Took it for a test run and nothing comes out of the peehole. Motor ran great and shifted fine. Never got to warm but only ran it no longer than 5 minutes at a time. Does it have a thermostat? Or should the peehole be going from start even if it does have a thermo. Thanks
 

backyard mechanic

Petty Officer 1st Class
Joined
Jan 6, 2009
Messages
203
Re: 72 mercury cooling issue

I don't think the 72 4 hp model had a T'mo stat but either way you should always pee. I'd suspect sand, or some obstruction in the tube or the hard plastiuc tell tale part. I enlarged my pee hole to allow for sand to flow through. Sometimes an air hose blasted at the pee hole while running is all it needs. Other times you yank the tube off and clear out the hole backwards.

I did have a salt build up stop the pee hole once. Salt terminator works well to prevent that.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,095
Re: 72 mercury cooling issue

Ayuh,... Replace the Impeller...
 

DuckCowboy

Recruit
Joined
Nov 26, 2009
Messages
3
Re: 72 mercury cooling issue

Ok. Tore it down, replaced impeller. A ton of water was in the gearcase so replaced oil. Test ran and peed fine but alot of oil in my test tub of water. Checked the gearcase after run and was milky so I replaced pump housing/drive shaft and shifter seals along with drain and vent gaskets. Prop hub looked clean so I left them alone. Put new oil in. Test ran it today Peed good for a bit then it went off and on to nothing at all. Alot of exhaust coming out of pee hole when it's not putting out water. Any ideas? Also my water was clean this time but oil was milky again. I'll check it again tommorrow. You think it's arriatted? As I've seen some people talk about or water? Any info or input would be greatly appreciated. Need this thing in tip top shape by the start of the second leg of duck season. Thanks

Bill

P.S. I would like to install a water pressure gauge and a tach. Since this motor has no gauges how would you go about doing this? Thank
 
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