EXHAUST PLATE 1976 MERCURY OUTBOARD 1150

[opalized1]

I PICKED UP ANOTHER MOTOR, AND FIRED IT FOR THE FIRST TIME LAST NIGHT, ON MUFFS, FIRED RIGHT UP, ONCE I REPLACED STARTER, REPLACED ALL WIRING INSIDE COWLING, AND FILLED ALL CYLINDERS WITH WD-40 AND ROTATED FOR AWHILE TO UNGUM, ONCE FIRED EMMEDIATELY PEE'D, BLEW BUGS AND CRAP CLEAR TO THE BACK OF MY GARAGE ON INITIAL START UP, SEEMS TO RUN GREAT, BUT, I NOTICED WATER RUNNING DOWN EXHAUST PLATE FROM ABOUT HALF WAY UP ON SPARK PLUG SIDE OF PLATE??? DOES NOT APPEAR THIS PLATE WILL COME OFF WITHOUT SEPERATING POWERHEAD FROM UPPER UNIT, WHICH I AM GUESSING REQUIRES REMOVING TRANSOM MOUNT AS WELL AS UPPER UNIT??? ALOT OF WORK IT WOULD APPEAR, AND ADDITIONAL PARTS.
NOW IS THERE NOT AN INNER AND OUTER PLATE ON LEFT SIDE LOOKING AT SPARK PLUGS, AND IF ONLY OUTER PLATE IS LEAKING IS THIS A MAJOR ISSUE TO BE RESOLVED PRIOR TO USING THIS MOTOR?? IT APPEARS IT HAS SEEPED DOE QUITE SOME TIME, AND SPARK PLUG IN HOLE 6 WAS BRAND NEW LOOKING AS WHERE ALL PLUGS SO IT WOULD APPEAR NO WATER IS ENTERING CRANK CASE

 

[GA_Boater]

Please turn off your caps lock. We don't need to be yelled at and it's easier for us to read.

Is the water leaking around the circled plug? That cover is not the exhaust plate, it's the cylinder block cover and the gasket can fail around the plugs. You may or may not need to lift the power head to remove the cover and replace the gasket.

The exhaust plate is on the left that the plug wires pass over.

 

[Chris1956]

If water is leaking around a spark plug, I would dry the area out and put some caulk on it. That should stop the leak. Removing the head water jacket cover or the exhaust cover can be difficult on those old motors. A lot of times the bolts break. It would not be unusual if 1/2 of the bolts broke.

To remove the water jacket covers, it is not required to remove the powerhead, but it sure makes it easier to coax out the bolts.

 

[opalized1]

No Title

The water as seen in second picture, is running down edge under spark plug wire retainer, appears to be coming from about half way up outter exhaust cover plate, not the inner exhaust plate. There is nothing leaking around the # 5 plug, just the wd-40 id sprayed in the motor to loosen it up before I fired it for the first time, it had been sitting a very long time id guess, couldn't hardly turn it over, really gunked up, some wd-40 and rotating it for a bit and more wd-40 it loosened right up, once I put gas and power to it, with the help of alittle starter fluid it fired instantly and idled like a champ.

per picture you can see signs of a leak that appears to have been occurring for quite some time, does not appear that the water is entering crankcase or spark plug holes all plugs are clean and motor runs very good, and engine pees pretty good considering the impeller is probably junk, I have not replaced yet, and considering the amount of time I believe this motor has sat, its surely rotten (impeller)

 

[Chris1956]

Well, put some silicone on the exhaust cover leak to seal it. Run the motor for a while and inspect the spark plugs. If they are all about the same dirty color, you do not have any water infiltration. If one or more spark plugs are real clean (like new), you likely have water infiltration.

Have you cleaned the carbs? Rebuilt the waterpump? checked the timing? All good things to do if she has been sitting around...

 

[opalized1]

impeller to be replaced prior to hanging motor on boat, carbs, when I pump primer bulb, once the bulb is firm, a small amount of fuel drips out top and middle carb, after a few drops it stops, so I am guessing needle and seat not sealing perfect, which would require a cleaning of the carbs.
Timing, clearly once hung on the boat, I will have to perform a link and sinc.
I have read the instructions 20 times at least, but I have extreme difficulty, I read something, and then my pea brain injects thoughts, link and sinc, pull throttle cable off, pull lower 5 plugs insert in spark plug wire and ground, rotate motor with timing light on # 1, first problem, motor only rotates with key on, and it fires and idles perfect on the #1 cylinder. Problem 2 im at 4500 ft above sea level, so my brain says, idle should be 4 degrees before tdc, instead of book which is tdc, then at throttle open, 4 degrees before tdc, total 31, 28, 24, or sticker #
Boat runs at 4500 to 6500 ft above sea level, so would you not adjust the factory specs for this altitude change??? by approx. 4 to 6 degrees?
my 95, I was able to get it running nice, by setting base timing at idle at about 5 degrees before tdc, then carb initialization, at about 10 degrees before tdc, and total advance around 38 degrees
What is right, do you advance timing for altitude on the 2 stroke motors?

 

[Chris1956]

Mercury does not recommend changing the timing for altitude running. They do recommend changing the main jet for altitude running. 5000 feet is the minimum altitude for the jet change. I would try the stock jets before changing them.

Idle pickup timing for that motor is 4-6* BTDC. Max spark advance is 21*BTDC. You can jumper the starter solenoid, key on, to check timing.

I would recommend you get a factory service manual for that motor. Idle pickup timing is when the carbs are still closed, but ready to open. Obviously max spark advance is the max advance. This will be reached before carbs are fully open. Some will recommend a 20* max spark advance, but 38* is way out of the range. Stick to the Merc specs, input from your brain is not needed.

 

[opalized1]

Link and sinc, final step really should be performed in water under load?
at which point optimum timing would be tdc at idle, 4 to 6 before at carb activation, then 21 degrees max at approx. 3000 rpms?
idle at 500 to 600 rpm optimum when in gear?

 

[Chris1956]

Link and synch can be performed on a trailer. First set timing pointer accurately. Measure from cylinder head water jacket cover to top of #1 piston. Add .464 inches to that measurement. Turn flywheel until timing pointer reads .464" BTDC. Check measurement to top of piston against predicted value. Adjust piston (if necessary) to proper measurement, and set timing pointer to read exactly .464" on timing decal. Install spark plug #1.

Remove prop and spark plugs 2-6. Put spark plugs into their wires, tie the bases together and ground them. Timing light on #1.

Crank motor, ign on,by jumpering starter solenoid. Adjust throttle (in gear) until timing is 4-6*BTDC. Now adjust brass colored collar by loosening two small bolts (5/16" wrench), and rotating collar until carbs are ready to open, but still closed. Tighten bolts.

Advance throttle full and crank motor. Adjust max spark advance set screw so timing is 21* BTDC. Adjust throttle stop set screw until carbs are fully open, but just short of carb stop.

Install spark plugs and flusher. Start motor and adjust idle speed using idle stop screw and throttle cable adjustment, until idle speed is 900 RPM.

Carbs need to be adjusted in water, under load

 

[UKMike]

Hi Chris,

Would this link and Synch work the same for my Merc 135 V6 Blackmax 1986

 

[Chris1956]

Mike, the link and synch should work for you, but since you have ADI ignition, the primary pickup timing is different, and the way you adjust the timing points is different.

You will want 0-9* ATDC for primary pickup. To get this, push throttle closed. Crank motor and adjust primary pickup set screw (just above pivot point on throttle arm) to correct primary pickup.

The max spark advance set screw should be just above the primary pickup set screw. Adjust to 21*BTDC, with the engine cranking.

That is an approximate procedure, as different models have slightly different throttle arms and set screws. I would recommend you study the throttle arm and determine exactly what each set screw does. There are idle stop, primary pickup timing, max spark advance and throttle stop set screws. Figure out which is which, Also, a service manual is a very good idea. Try to get a factory one...

 

[opalized1]

Thanks Guys, got the motor hung on the boat sunday, so first chance I get ill be heading for the lake to make final adjustment, and see what I have, the 950ss ive been running, had some cross fire, and I never really got all it had, this motor seems far better in that area, so hopefully, the prior top speed of 32 mph will be eclipsed by maybe 10 mph