guy I no I have a mercury but....

johnbates

Petty Officer 3rd Class
Joined
Apr 14, 2004
Messages
89
no one will answer me so maybe someone can help me here..I went on the lake today to try the motor I just bought..I only noticed a mist come from the exhaust water port..is that all there is or should it be alot
 

Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: guy I no I have a mercury but....

When you say "exhaust water port", are you speaking of the tattletale?<br /><br />c/6<br />Hooty
 

cobra 3.0

Lieutenant Commander
Joined
Jul 31, 2003
Messages
1,797
Re: guy I no I have a mercury but....

There should be a pee hole and it should run a nice stream of water all the time. If it doesn't, check the impeller (water pump).
 

Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: guy I no I have a mercury but....

...or see if the pee hole is plugged up.<br /><br />c/6<br />Hooty
 

johnbates

Petty Officer 3rd Class
Joined
Apr 14, 2004
Messages
89
Re: guy I no I have a mercury but....

I dont see any pee hole..On the mercury motor there,s a square hole about 4 inches below the power head..I dont no much about motors
 

ledgefinder

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May 2, 2002
Messages
916
Re: guy I no I have a mercury but....

What model & year Merc do you have? If you don't know the year, how about the serial number. Older Mercs didn't have a pee hole. <br /><br />With the cowling off, on the port side of the motor, find the big exhaust plate. It'll take up most of the rear half of the motor on the port side. If your motor's cooling properly, that cover should be either about the same temp as the lake, or a little warmer (on the new ones that have thermostats - say from the early 1980s on up). <br /><br />The 35-70hp Mercs have REALLY wimpy water pumps. If you have one of those, and the impeller hasn't been changed in a while - that's probably your problem right there.
 

johnbates

Petty Officer 3rd Class
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Apr 14, 2004
Messages
89
Re: guy I no I have a mercury but....

well my motor is a 1964 mecury..4 cyl 65 hp..theres a sqaure hole about 8 inches below the power head...well when i put my hand there all I get is a little mist..is that what its supose to be??? model # 4 D serial # 1623793
 

ledgefinder

Ensign
Joined
May 2, 2002
Messages
916
Re: guy I no I have a mercury but....

OK, I think that's too old to have a telltale. Is the exhaust plate cool? Should be about the same temp as the lake/ocean you're running in; maybe just a hair warmer. <br /><br />The mist may be fine. The square hole is an exhaust pressure relief. Outboard motors spray water into the exhaust to cool it. Expect a little mist at idle, and a heavier "rain" when running at high throttle/rpms. <br /><br />I'd change the impeller, unless you know it's been done within the last year or two. If the impeller fails, the first warning you'll get is when the motor seizes up from overheating. It's not too much of a job, unless the driveshaft is stuck in the powerhead. At the same time, grease the splines on the driveshaft & propshaft. Those old Mercs have a plain carbon steel driveshaft (not stainless), and they will rust up otherwise - particularly if you run them in saltwater.
 

johnbates

Petty Officer 3rd Class
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Apr 14, 2004
Messages
89
Re: guy I no I have a mercury but....

I dont know much about boat motors is the exhaust plate right above the square hole
 

ledgefinder

Ensign
Joined
May 2, 2002
Messages
916
Re: guy I no I have a mercury but....

You have to remove the cowling (band) to see the exhaust plate. <br /><br />The exhaust plate is on the port (left) side of the motor, and covers most of the back half of the left side of the motor. It's a big flat plate back there. It's cooled by water (internally) so if your cooling system's working properly, the exhaust plate should be cool.<br /><br />The area above the square hole, on the back of the motor where the 4 spark plugs go, is the cylinder head.
 

ledgefinder

Ensign
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May 2, 2002
Messages
916
Re: guy I no I have a mercury but....

By the way, the ledges I find are usually those in Muscongus Bay - Friendship/Waldoboro. How's the weather down there?
 

johnbates

Petty Officer 3rd Class
Joined
Apr 14, 2004
Messages
89
Re: guy I no I have a mercury but....

trying to change water pump pepeller how do i get the unit apart....is there any linkedge i have to unhook help its a 1964 merc. 65 hp 4 cyl
 

ledgefinder

Ensign
Joined
May 2, 2002
Messages
916
Re: guy I no I have a mercury but....

No linkage to undo. Make sure you get all the nuts. There's one under the skeg (that aluminum fit at the back of the lower unit).<br /><br />If you're sure you got all the nuts, & it still won't come off, the driveshaft splines may be stuck in the bottom of the crankshaft. As I said, common on those older Mercs. Work at it for a bit, being careful not to break any of the castings on the lower unit (easy to do). <br /><br />Still stuck? OK, remove all the nuts but the two in the center of the lower unit. I mean the two studs facing UP in the center of the lower unit. Don't remove those nuts, just loosen them up about 3/8 of an inch. Now back the boat/motor/trailer into the water at the launching ramp, fire up the motor, and GENTLY run it in forward and reverse a couple times. <br /><br />Often that'll do it. In forward, the thrust from the prop tries to rotate the lower unit forward out from under the motor. The reaction force tries to pull the driveshaft down. Combined with the shock, vibration and heat, that'll often do it. If you can't make it to a ramp, running on the flushmuffs in the driveway might do it.
 

moderator1

Lieutenant Commander
Joined
Dec 5, 2002
Messages
1,668
Re: guy I no I have a mercury but....

Moving to Mercury Troubles and Repair.
 
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