TOPIC: Finding coils for a 71' 7.5 HP Updated!

I have had 2 coils on order for two months now.
I have scoured the net.
Are they really going to make them?
I did call, they said other orders were in there as well as mine.
No word from the mfg.
336-4409

Are they the lime green coils? I probably have some good used ones. Are you changing them because you know they're bad or are you trouble-shooting your motor by swapping parts? Those motors have the maker point ignitions and the problems are generally not coil related, rather are arc-path related in the area of the points. Either that or the electronic donut has given up its smoke.

try www.twincityoutboards.com Located in Shakopee, Minnesota. LOTS of old and NOS parts for most all outboards

OK I have found 1 new on ebay, and have possibly located the second on ebay (used) as well.
They are physically broken where the small wire exits the rubber housing thing going into the block of the coil itself.
They are dark green.
If anyone has some I would like to know.
This engine looks showroom new.

I did some troubleshooting, as I was ready to change the stator.
The stator puts out the 400+ VAC and I get contact from the points as I rotate the flywheel.
It was then I started looking at the coils and noticed one was broken. But no spark on either cyl. Looked at the other, and it had been glued in that exact spot. In the middle of that exact glue spot is black. It arced over and likely opened.

OK, coils were not the problem! AAAAhh!

No spark whatsoever.

Here is what I have done.
400+ VAC coming from stator green wire to gnd. ( green disconnected).
Checked brown and white coming from stator for continuity while rotating flywheel. It opens and closes as manual says it should.
Checked stop switch. It is shorted, opens when pushed.

What am I missing?

I read somewhere on the internet about an insulator block frequently going bad.
Drawing in my Seloc manual shows it.

Should flywheel be coming off now?
Where can I get the proper flywheel puller for this engine?
Serial # 3181847 1971 7.5 HP.

Any reason I couldn't use my OMC puller? I took the starter off and it looks like the OMC puller is perfect for it.

As long as you're using a 3-bolt harmonic balancer puller, it doesn't matter what it's for. Use grade 8 bolts...

The OMC puller worked perfectly.
I found one of the wires from points to one coil was very floppy. Half the strands were broken, and lots of corrosion inside the wire.
I am going to change the wires and insulator block, maybe points.
Any other suggestions?

points are very expensive.

Still working on it.

I just finished replacing the insulators and wires that go from the points to the coils.
The solder was covered by some type of black insulating material at the place in the insulator where the wire attaches to the screw.

What should I use there? Is there such a thing as electrical insulating silicone?

Thanks
Jim

Crowley Marine has them .. you can get it in overnight delivery ,you pay extra for overnight , I got parts in 1 day from them !! scroll down to #35
www.crowleymarine.com/mercury-outboard/parts/444_5.cfm

I have new coils already installed.
Took a while to find them. (two different sources)

Believe me, just because it says in stock, or ships in 3-5 days, that likely isn't the case with this engine's parts.
I ordered coils from 10 different places.

One came from ebay, and one from a marine store in Wyoming, MN.

I was told from one place that I ordered them that they were on order from merc. and that they would be made. I would guess that every 5-10 years if demand warrants they will spin some new coils, but not until a sufficent quantity is needed. That day now likely won't come. One coil I bought had a date code of 1987.

I have hope that this engine is going to run in a few days assuming I put it back together correctly, and the points are ok.

Thanks.

Listen to Chinewalker on this, he knows what he is talking about. The '70-'71 ignition systems on these motors are bass-ackwards from other Merc systems in that the points fire when they make contact, NOT when they open to .020". A good way to check your coils and stator is to disconnect the brown and white wires from the coils, then clip a jumper wire to the negative terminal of the coil. Have a friend pull start the motor while you carefully tap the jumper to engine ground. If the coil fires, check your points and points wires for the problem. Pitted points are normal, but they must be clean and shiny. These systems put out a HOT spark when everything is in order, but like most Mercs, you should replace all the wiring as the original wiring is likely rotten. According to tech support at CDI Electronics:

Troubleshooting
No fire at all or only fires on one cylinder:
1. Use a jumper wire and short the orange (Salmon) wire to ground. If the engine starts, use the
choke to kill it and replace the kill switch.
2. Disconnect the points wires from the ignition coils and connect a jumper wire to the negative side
of the coils. Crank the engine and carefully tap the jumper to engine ground, if the coil fires –
check the points and points wires. If it fails to fire, inspect the ignition coil. You should have either
a red, orange or green coil with a ground wire coming out of the backside of the coil. This braided
ground wire MUST be connected to engine ground. You cannot use a black or blue ignition coil.

The coils were not my main problem, but they did have broken ground wires. I did get the correct one. The wrong ones were easy to find.
The white wire from points to one coil was really bad inside.
One insulator was cracked.
I will spiff up the points as much as possible.
I have verified the 400+VAC from the stator.
I have never worked on a merc before, and it has become my white whale. It is going to run. It looks new.

Thanks

YESSSS!!!

We now have spark.
More details tomorrow I hope.
Need to modiify a hose to run it.

If you run that motor on a hose or flushing attachment, make sure you don't use the kill switch to shut it off, use the choke lever to kill the motor. According to CDI electronics, using the kill switch can burn out the stator if the prop isn't in the water.
Did the insulating blocks restore your spark?

I tank tested it yesterday.
Ran perfectly.
Yes, it was either the insulators, or the wires.
I sanded the points while I was in there. They were still at .020.
The stator is original and I do use the kill switch.
No way to run this on muffs.

I have wondered about the warning from CDI. Since there is no way to run it unless it is in water, then it shouldn't be a problem. I am sure the previous owner used the kill switch. I wonder if the stator from CDI is electronically different then the original.
This engine is cosmetically near perfect.