1963 Mercury 500 50hp

bgc

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Jul 13, 2011
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I found a 1963 500 motor and have been working on getting it ready for the water. So far,

The first thing i did was pulled the plugs and put KROIL into the cylinders to free the piston rings and every nut, bolt, dohicky I could find.

I pulled the flywheel to replace the timing belt;

They're not kidding about the chore of pulling them. Tighten the puller to the point you think it should go and then tighten some more. You will find it still wont come off so tighten it to the point something should be breaking and strike the center bolt of the puller with a hammer and it will pop off.
The timing belt pulley is connected to the bottom of the flywheel and there is little clearance between the pulley and side of the housing to slid the flywheel off. I gently rotated the flywheel working the belt off the pulley for some time. Installation is the same way.

I changed the condenser, cleaned the points, and oiled the wick for the points cam.
An off set, opposing, right angle screwdriver will come in handy for removing the distributor and magneto caps as someone with a sick sense of humor and small hands built this part.

The water impeller replacement is straight forward. Remove the anode, the nut under the anode, the nut near the anode, and the two nuts under the anti-cavitation plate. I use a bit of grease to help get the new impeller into the housing.

The carburetors on this motor have been made for years and many of the parts are available from Mercury. As are the check valve kit/fuel pump kit and the fuel lines.
The carbs are easy to rework. Keep the parts and work area clean and count the number of turns when removing the idle needle. This will help when you go to start the motor.
The fuel pump is simple but the screws that hold the check valves can stick. Take the housing and place it on a sturdy piece of wood on the floor. Apply some good penetrating oil to the screws. Insert a #2 philips screwdriver into the screw head and firmly strike the back of the driver with a hammer. Let it sit overnight and the screws may come out.

While installing the new spark plugs I found the spring coil at the ends of the wires have rusted way.

After 35 hours and some swearing I was ready to start the motor. I mixed the non-oxygenated gasoline and oil at 24:1 and added 1 ounce per gallon SEAFOAM. The motor is a pull start (WHAT KIND OF SICK PERSON HAS A PULL START 4 CYLINDER) and it fired the third pull only to have no water coming from the pee hole. I found some mud in the hose coming from the top of the engine.

All said and done i had the motor running/smoking out the neighborhood for an hour last night and a brisk idle. :D
 

Mi duckdown

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Apr 14, 2007
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2,575
Re: 1963 Mercury 500 50hp

Nice job. more people should have your state of mind.
Did you do this without a manual?
Check the compression, just for the heck of it.
Nice.
And you have cable steering. Sweet
 

bgc

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Messages
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Re: 1963 Mercury 500 50hp

I did not have a manual, just the good folks here and the knowledge of mechanics my grandfather passed on to me.
I am going to hook the gauges up to the motor and get a base line of what its doing.

The boat is a 1963 Starcraft 15? Jet Star and the 500 is the motor that has been on the boat since it left the showroom (previous owner had saved registrations). It has the original steering wheel, in oppelecent white and the steering cable setup. We took it out on the water for the first time in last night. Wow, that little runabout fly?s with that engine at WOT.

However I did find I still have a fuel delivery issue. Somewhere there is still an air leak that shows itself under heavy throttle. Also the top carburetor is dripping fuel out of the bottom brass plug, its tight but still drips. Anyone ever use thread sealant on this part?
 

MacDaddy21

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Feb 16, 2011
Messages
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Re: 1963 Mercury 500 50hp

I've seen some carbs use a teflon or similar thread sealer. I think it is okay to use. But if you are talking about the bottom plug that allows access to your jets, I wouldn't recommend that you seal it with thread sealer because if the jets ever get gummed up you'll want to be able to pull them. The carb rebuild kit should have a replacement O-ring for that bolt. Look for one of those, probably your best bet. Great work on the motor. I did mine the same way, no manual, just posted on this forum and worked my way through it. Very rewarding feeling.
 

bgc

Ensign
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Jul 13, 2011
Messages
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Re: 1963 Mercury 500 50hp

Its not the bolt that is dripping its the pulg next to the bolt. I found a non hardening thread sealer at Grainger rated for exposure to multiple fluids. I am going to give this a try before I use the hardening type unless someone out there knows how to solve this.
 

merc850

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Jul 7, 2010
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2,026
Re: 1963 Mercury 500 50hp

Post a picture of that leak for better instructions.
If you have to do the points again the whole magneto assy. is removeable by undoing the 4 bolts (on the top) that hold it to the adapter assembly. It is important to make sure that the magneto shaft is centered in the red magneto housing and the rotor is held on with a couple of drops of Loctite.
You can run the motor at 50:1 with Mercury's oil and if you are confident 75:1 with synthetic (Amsoil).
 

194269

Petty Officer 2nd Class
Joined
Jul 9, 2011
Messages
104
Re: 1963 Mercury 500 50hp

My 7 years experience at OMC and 2 years at Mercury Marine tell me otherwise. Yes you can run at 50:1 and 75:1 and you can run at any ratio you want. If you want it live for a long time, run at 24:1, thats where I run all my engines.
 

bgc

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Messages
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Re: 1963 Mercury 500 50hp

OK, I have replaced all of the fuel lines and reworked the fuel tank, issue has gotten worse. Everything is sealed and the motor still acts like it is starved for fuel or has a large vacuum leak.
It will start up and idle but when put in gear and give it some throttle it dies. I did this several times before pumping up the bulb and then hitting the throttle, it took off. I ran it at WOT for about 10 minutes during this time it kept coughing. I shut it off and when to the dock, tied off and restarted. It did not want to idle. I turned the idle screws down (less fuel) and the engine smoothed out at a faster idle but still died when giving throttle.

Any thoughts?
 

bgc

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Re: 1963 Mercury 500 50hp

Tonight I replaced the needles,seats, and floats, replaced all the carburetors gaskets, replaced the fuel pump diaphragm (again), replaced the pressure side fuel line, and the spark plug boots/ends.
 
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bgc

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Jul 13, 2011
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Re: 1963 Mercury 500 50hp

Something worked, it still has a rough idle and will not slowly accelerate but when I punch it, it ****s and gets.
 

coolguy147

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Jul 14, 2008
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2,817
Re: 1963 Mercury 500 50hp

24:1

the bearings can handle the 50:1 BUT! the motor was not made to scavenge for oil with a 50:1 mix.

24:1 is the right mixture


a annual decarb would be good too:rolleyes:
 

coolguy147

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Jul 14, 2008
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Re: 1963 Mercury 500 50hp

you need to adjust the carbs

set each low speed idle jet to 1 1/2 turns out from LIGHTLY seated.

do one jet at a time.

after you adjust them while in forward gear. do a holeshot test. if it falls on its butt. bring each needle 1/8 turn out till it gets better
 

bgc

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Jul 13, 2011
Messages
980
Re: 1963 Mercury 500 50hp

Its doing better each time I get it in the water. Still has a cough at idle and does not like to accelerate slowly.
I cannot get the engine to idle with the carburetors completely closed. It will run with the idle screw pushing the butterfly open.
I did not use a drill bit when cleaning the ports in the carburetors just spray cleaner and a tooth brush.

Any thoughts from someone that has had this issue?
 

coolguy147

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Re: 1963 Mercury 500 50hp

why would you use a drill bit to clean the jets?!?!?!?!?!?!?!?!?!?!?!:mad::confused::eek:

you need to make sure that the motor is synchronized.

http://www.maxrules.com/oldmercs/timing/64.pdf
http://www.maxrules.com/oldmercs/timing/65.pdf
http://www.maxrules.com/oldmercs/timing/66.pdf

http://www.maxrules.com/oldmercs/timing/5.pdf
http://www.maxrules.com/oldmercs/timing/6.pdf
http://www.maxrules.com/oldmercs/timing/7.pdf


the holeshot sounds ok. it depends on how big your boat is.

some will be just like your engine. some will not.

you can see what you can do.
 

bgc

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Jul 13, 2011
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Re: 1963 Mercury 500 50hp

Service manual says to use drill bit for cleaning passages/ports in carburetor.
 

bgc

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980
Re: 1963 Mercury 500 50hp

Did some more work.... http://www.youtube.com/watch?v=4zxYUYl_G3c

Coming off a plane to idle, it runs smooth for about 30 seconds and then starts coughing. It will continue to cough and sputter through mid throttle when accelerating. I have now cleaned all the passages with a bit and vice, could there be too much fuel during idle?
 

coolguy147

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Re: 1963 Mercury 500 50hp

it's really hard to tell without me actually being there.


like i said before, you need to do a synchronization between the timing and carbs.

then doing a carb adjustment by setting the idle screws to 1 1/2 then adjust. one carb at a time. adjust out to get good holeshot ok idle.

read the links that i posted up!!!!


don't touch the max advance screw you KNOW it's been touched. generally people don't touch it but it if you don't hear back fire or pinging at WOT or close to then you should be fine.
 
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