TOPIC: Ignition key broken

My troubles never seem to end
The key was broken off in the ignition about 4 years ago, since then we have just been inserting the remaining part of the key, but now that part is lost. Now I can't get the remaining part of the key out of the ignition (tried a number of methods shown on youtube but no luck). Has anyone tried to take apart the ignition cylinder?

Also, the label on the ignition is 123 then underneath A51015. I'm guessing the key version number is 123?

The 123 would be the correct key number from Merc.
I have the 123 key & can have a copy made for you if you are able to remove the old key.
I would think a locksmith would be able to remove it pretty reasonably if you took the boat (or control box0 into the business.
doc

Thanks Doc.
I've taken the ignition out of the control box (needed to get in there anyways because the choke button was corroded from when it sank!). I'll see about going to a locksmith tomorrow.

And,...Not sure if you are aware of it, but that choke button assembly can easily be disassembled and cleaned rather than needing to replace it.
doc

Thanks Doc.
I was able to get the key out after all What better way to spend a Friday night
I thought I would post a picture of my tool and the end result. I made the tool by filing one arm of a pair of needle nose tweezers. I made it thinner and not as wide then filed a little notch in the end. With this, I was able to slide it in past the end of the key pull it out. It took a while to get it right, then the key would only come out part way (it seemed to get caught when it was almost out. I think it was the broken sharp part of the key that got stuck. So few taps got it the rest of the way.

I'm going to hunt around for an old Merc store around here (I don't hold out much hope). If it doesn't pan out, how do I get my contact info to you?

(Thanks for the tip on the choke. I took it apart and sure enough it was pretty kunked up. Also, the red wire had broken off)

You can get new keys from oldmercs.com, five bucks each.

Thanks for the offer Doc and the suggestion gf. I was able to get a key from, believe it or not, a dry land marina in Toronto (no where near water). So now I am good with the key but, there was one wire that was broken off (I didn't do it I was being very careful) and although I pretty sure it would attach to the only post open, I am not %100. Would someone be able to confirm the wiring? I've searched all over the internet and have only found one site with some information, but the diagrams don't match up with mine. I have:
B - Yellow
E - White (or could be light brown)
A - Black (goes to the choke)
D - open
F - Green
G - Grey
The wire that is broken off is Red.

What motor is it. makes a difference.

I guess that would help! It is a Merc 300

66 post 66
A-red - green
B-yellow - yellow
D-black - red
E-salmon - white
F-white - black
choke-gray - blue w jumper to F

from mercury service manual
there are many harnesses that work yours may be a later one. trace the wires and see where thy go in the motor is the safest way.

Thanks for the reply Dave.
Yes, the harness must be different. For sure on my ignition switch there is a black wire coming from post A to the choke. Also, my switch has G post. Tracing the wires to the engine will only get me half the story since I don't know what the post labels mean.

Hi,
If your present ignition switch does have a "G" terminal (six terminals in all), it is for a 2-cylinder, but would work fine with the sixth "G" terminal unused. A picture(s) of the wiring might help to better understand why the color codes are different.

Regards,
Joe
www.fergusonpoolemarine.com
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Here is a picture. From the look of the wiring it appears to be original. We have had the engine for over 30 years and I know we have not messed with the wiring. I guess there is a chance that the previous owner did, but by the looks of the sealant that was on the wires (I scraped it off for the pictures) I think it is original.

I little difficult to tell in the picture, but the black wire running from post A goes to the choke where another black wire splits of it. The other post on the choke has a blue wire.

The wire coming off post E looks light brown but I think this is from oxidation. Looking at the cut portion (now shown in the pictures) it looks to be white.

So the missing wire, which I am assuming broke off post D (which does have some solder) is Red. But...when I took the ignition apart the red wire was sort-of taped to the yellow (not with the wire making contact, only the insulators).

The red wire goes to the rectifier.

Study the wire diagram carefully as it shows color codes for both the prior to '66 & post '66 engines with a magneto.
It appears to me that you have a pre '66 ignition switch.
The red wire going to the rectifier is not related to the red wire in your ignition.
The red wire to the rectifier is 12vdc+ while the red wire in your ignition switch is actually negative (-) ground.
Be very careful, disconnect all wires from the internal harness to the various engine components and do continuity tests on each wire to identify which pin each wire is actually connected to.
You may be scratching you head a few times, but it will start to make sense after carefully reviewing the attached pictures.
Doc

Thanks for the details Doc.
I started scratching my head, then pulling my hair out and now I feel like smashing my head against the engine. Something is wacky. I've gone over this a few times so I think the information I have below is correct. Either I didn't trace the wires correctly (five times!) or this is really how it has been set up. I made two tables. The first table shows the connections indicated in the service manual (it also matches the picture you sent). The second table shows the connections on my engine.

1-looks like the rectify doesn't have a wire going to the switch. I traced the wire from the rectifier to the connection base to the center post (engine side). But there is no connection from the plug to the switch.

2 - as mentioned, the red wire on the switch side was not connected. This flows through to the negative bat lead.

3 - the black wire coming from post A (that also goes to one post on the choke) doesn't have a termination.

4 - the starter solenoid terminates at post F instead of A as shown in the manual.

The switch is model A51015.
The connections are all as they were (with the exception of the assumption that the red wire at the switch was at one time connected) when the engine was last run.

I'm not sure what I should do now

Some more pictures/documentation:

Hi,
You have been given excellent advice by Dave and Thom (Doc). It would seem that you are assuming that all is factory original. If this is the case, it is certainly not true, as the plastic housing ignition switches were not seen for almost a decade after your outboard was produced (the original switch from the same manufacturer was an aluminum housing in 1960). Therefore someone has "rigged" it to work, and this is causing the great confusion. I have studied what was done, and I can see how it would function, but I would highly advise you to return the wiring to the factory scheme as Dave and Thom have advised, and the next time, or the next person who must work here again can avoid repeating this issue. So, connect the:
Green wire to "A"
Yellow wire to remain to "B"
Red wire to "D"
White wire to remain to "E"
Black wire from harness to choke switch and jumper to "F"
"G" would be unused, but it can still connect to the control case if desired

Think of it this way. When the key is "off", the Red (the ground wire), the White (magneto grounding wire), and "G" (the additional magneto grounding wire point for a 2-cylinder with two breaker points) are connected together. When the key is "on", the Green (12 volts from the battery) and Black wire (connects to the center terminal of the engine harness plug - to the rectifier as you note). This output of the rectifier is also connected to the main + battery cable in the engine harness itself (so the person who "rigged" the wiring did not have to worry about this). The choke switch would only have power when the key is "on" this way. The "G" terminal was "rigged" as battery ground, but with the proper connections, this is handled by the Red wire, and is does not matter anymore.

Good Luck,
Joe
www.fergusonpoolemarine.com
This email address is being protected from spambots. You need JavaScript enabled to view it.

Thanks for detailed write up Joe.
I guess I was worried that someone rigged it up differently for some reason. I'll take your advice and re wire as per spec. I'll have to diagnose why the black wire doesn't terminate in the center post of the plug.