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Installing a magneto in 52 K model

PostPosted: Mon Apr 15, 2019 4:31 pm
by K Daddy
magneto mounting.jpg
magneto mounting.jpg (141.41 KiB) Viewed 13516 times


I want to use a magneto on my 52 K model. Today, I removed the distributor and put the magneto in its place. It is clear one or more parts are missing. There is a 1/8 inch gap between the mag and the case. I remember my brothers 66 Sportster magneto and the spark was retarded by the left hand grip and the spark was advanced when the engine was running.
Looking at the 59 Sporty manual, exploded view 5F-6, I think I need item 47, adapter. Item 26, drive housing, is already installed on the mag.
Maybe that is all I need.
Yes, I know I seem excessively ignorant but I got this bike for free, but mostly disassembled with many parts missing. So I am learning as I go.
Thanks in advance

Re: Installing a magneto in 52 K model

PostPosted: Mon Apr 15, 2019 6:15 pm
by Mark.A
I think you need part # 29600-62 adapter plate

Re: Installing a magneto in 52 K model

PostPosted: Mon Apr 15, 2019 6:32 pm
by mikeslemmon
the adapter plate may be a -55 part if it's an early mag without the tach drive. the HD parts books ' 53to '63 and '55 to 65 don't give a part#. the the only difference is the location of the holes for the screwes

Re: Installing a magneto in 52 K model

PostPosted: Tue Apr 16, 2019 4:31 pm
by K Daddy
The magneto has an opening for a tach. I can see a tach drive gear in the opening.
Does this info help clear up what adapter is needed?

Re: Installing a magneto in 52 K model

PostPosted: Tue Apr 16, 2019 5:35 pm
by Ferrous_Head
OK, so no one else seems to be cjipping in. I'm not a K guy I'm a Sportster guy. So take what I say with a grain of salt.

Since the K, apart from the KR, never came with a maggy you have a little freedom as originality is obviously not that high on your list.
You have a couple of options. Anf they depend on what you want to do with the bike.

If you just want to ride/race it and you won't be registering it and riding around on the street you could go to the front mount magneto. Morris make these now. They are EXPENSIVE. But they are the best ignition for a maggy Harley available.
If you want to keep the generator you still have a couple of options.
The mags came with key locks and without. They came with tach drives and without.
They came with fixed adbance and with an advance/retard syste,

Assumimg you already own that mag in the picture you have the tach drive version which will also have an ignition lock.

The fixed advance system is by far the easiest. To use the advance/retard et up you nee a lt more parts including the correct handlebars, spirals plungers, cabe etc.
The fixed version just requires the 296200-62 base plate. There is a seal that goes into the shaft hole in the cam cover as well. You might need that. 023. It was an upgrade from an earlier seal.
You also need the corect screws to mount it of course.
On a Sportster starting can be an issue with fixed timing. Actually it can have an issue even with the advance/retard set up. But on the low compression K you should have no problems at all. (grain of salt there as well).
just don't expect it to start as easily as it does with battery/coil systems.

Re: Installing a magneto in 52 K model

PostPosted: Thu Apr 18, 2019 9:04 am
by K Daddy
Ferrous Head, thanks for the input on the mag for my 52K.
I would like to keep the generator so that I can have lights. Later on, I want to convert to a 12 volt system.
Originality is not an issue.
I do want to license it and drive it on the road.
I own the Mag seen in the picture. That is the mag I recently purchased setting loosely in the side cam cover to my bike.
I also have the correct handlebars and spirals. They are old and rusty but I think they will clean up and work fine.

My goal is to install the mag in place of the OEM distributor and be able to retard and advance the spark for easy starting.

My brother had a 66 xlch and I want to have the same retard / advance functionality on my 52 K model, if possible.
So if I find and install the 296200-62 base plate, will this give me the spark retard / advance I am looking for?
Will I need to modify the base plate to accept the seal you described?
Thanks for your input.

Re: Installing a magneto in 52 K model

PostPosted: Thu Apr 18, 2019 11:39 am
by Nitro57xl
No, that -62 plate is for fixed timing, if you must have the same thing as the 66xlch you need all the parts used on that. Your k model won't start easier with the timing retarded in my opinion, not enough compression. Others will argue, but, I have had a lot of experience with magneto Sportsters and never saw a benefit to retarding the timing when starting a magneto bike . You will have better luck learning how to kick it and proper mixture control if you want it start reliably. Most people either flood them or don't give them enough gas?

Re: Installing a magneto in 52 K model

PostPosted: Thu Apr 18, 2019 12:40 pm
by sportyparts
There are 3 different magneto bases, any one will work. Call me if you need one I have all 3. Kirk 714 879-0500

Re: Installing a magneto in 52 K model

PostPosted: Thu Apr 18, 2019 3:47 pm
by Redpan
Morris sells a retard device for fixed magnetos. It works.

Re: Installing a magneto in 52 K model

PostPosted: Thu Apr 18, 2019 5:55 pm
by Ferrous_Head
I agree with Nitro. There are repo parts on EBay to add the advance/retard but I also question it's value. Especially on a Flattie.

But if rhar
t is what you want you can do it. And yes again, the -62 is for fixed advance. The later seal upgrade drops straight in. Kirk can sell you the parts you need to finish it off. You need a cable and plunger as well.
I suspect a LOT of the hard starting issues is caused by a number of factors. Magnets do not retain their magnetism forever. They get weak over time. Especially if "knocked about" or exposed to heat.
Choice of capacitor (condenser)plays a big part too. Some have twice the capacity of others.
If your not that concerned with originality you can use a carb with an accelerator pump. That makes life easier.