Ignition - replace magneto with 'Sparx'?

Schwany said:

If this magneto dealio is for the N15 you are working on (beautiful work so far), as mentioned a small magneto housing would look best with the Thorspark EI inside it. The K2 is a monster size magneto. JH magnetos are shorter wider probably pretty good and would be a relatively easy install in the standard magneto location. To me the only advantage of a magneto is you can get away with not using a battery. Great for a race bike.

I had a big rebuilt Lucas K2 on my P11 for years. If my memory serves the brightness of the lights were RPM dependent when I had the magneto on there. Things may have changed for street bike lighting with a magneto and no battery since I did that though. I took it off in the early 1990's. If I were to ever use a magneto again, I'd keep the battery I'm currently using for the lights. It weighs less than my wallet. My current ignition system weighs less than $4 in quarters.

My opinion means nuts. I only responded to tell you I like the work you are doing on the N15.

Click to expand...

Thanks Schwany. Yes the N15 - since the K2F is what I have in hand, and funds are very scarce these days I am trying to use/mod it. The Thorspark seems the most cost effective way to get it running reliably and that's my goal. Happy to be advised good or bad though. I have coils, and hopefully one of my alternator/rotor setups that came with the pile works.

My other bike would like a magneto but it's doing fine without, putting down 185HP. Dyna S ignition and coils, Mr Turbo kit install and engine work by Don Vesco's shop when new in '82. Ran 184 MPH at Bonneville, it was mainly raced there and El Mirage, but on the street occasionally. Ex owner said he would power wheelie at 130 on the freeways and I believe him. Hope it's OK to post non Norton here but I'm proud of my resto and like the bike a lot.

It's your thread. Post what you want. I'm really good at not caring where a thread goes. 3 pages in I'm surprised the topic hasn't morphed to cupcake recipes.

Big bore air cooled Suzuki motorcycles make respectable beans without forced induction. That thing must be a unique ride. It certainly is clean.

I've owned a few Suzuki motorcycles. My '86 GSXR1100 had a front fork similar to that one you have there. Once setup it was as good as multi-adjust everything upside down Ohlins. The rear shock was garbage though. It would power lift the front end in 5th pretty easy, but I geared it fairly low for more gear choices when riding in the tight stuff. I've never seen 185mph on a speedo in my life. I've seen 173mph out on HWY 25 in CA, and stuff is going by pretty darn quick. Only did that once. After that stayed mostly below 140mph if I had room to roam. All that was fun but a lifetime ago.

Ha, thanks yeah I can certainly get side tracked. For instance - building from a pile of bits challenge: with Japanese bikes, hardware lookup is so simple. Any number of sites have the diagrams, most fasteners have the exact size. My process on the Norton is:

• Download parts lists and OCR for searching. I use a couple as I'm not sure of absolute coverage yet.
• Do a lookup on Andover or Walridge, noting that the number formats have either dashes (most do this it seems), dots (Andover) after the first two digits, or no separator (i.e. the parts list).
  • Or the number format has changed entirely - thankfully Andover references the different number formats and is searchable. Example: PLAIN WASHER 3/8" (00.0010, NME5376, NME5455, APCP2696-155) is part number 60.2322. I have no idea what all these formats are....yet.
• Verify it seems to be what I have, or need, and then go over to Stainless Bits - which is really helpful to get the sizing
• Measure the bolts from my bike until I find a match, and see if it's usable.
• Order if I don't.

I'm sure most here know all this stuff, but it's been years since I owned anything (and I mean ANYTHING) made in Britain and I never had to start from scratch. Anyway, I don't mind, I love a puzzle and a challenge.

OK well I concluded that I can't financially manage a ~$600 rebuild of the K2F magneto - I suspect a fair bit more once the full assessment is done. So I got a mini housing and Wassell MK2 setup for a bit more than half that. I can only research so much on this subject and pros/cons/opinions are endless. I don't want to open up any of that, I did what I did and will go with it.

Still, I could use some 'splainin'....

The housing I got looks just like the Tri Spark one. It has a tapered shaft. My AAU unit fits nicely on it, but obviously I don't want to use that unless absolutely necessary. I'd need to have it tack welded solid (gasp!). I am asking different vendors that sell this unit where I may find a solid 18T taper fit sprocket and hope to find out relatively soon if one exists in Norton land. The only 18T sprockets I see so far are for a non magneto contact breaker assembly and have a hole drilled in for a pin or bolt.

And speaking of pins, what puzzles me is: given the sprocket can go any which way on the shaft, how is this tapered type properly aligned so I can set the ignition timing? There's no woodruff key, no alignment marks that I can see. No info so far in my manuals, it just says 'reinstall' and set timing... Anyone?

The sprocket has no key way because timing is not set by the AAU and sprocket, but by the contact points that are driven by the AAU.

For detailed timing instructions, see ...https://www.accessnorton.com/NortonCommando/setting-up-and-timing-a-k2f-magneto.19685/

This is specifically for a magneto, but the principle is the same for points/coil.

BTW .... you can avoid tack welding the AAU by safety wiring the bob weights. I will grant that tack welding is better. Your call. If tacked carefully, it can be undone with a Dremel tool.

Slick

Not certain if I understand your question. There is no key or alignment mark on the sprocket that you use to replace the AAU because you have to begin the timing procedure by finding 32 degrees btdc or whatever other timing point you are using. (This is explained as part of Slick's instructions for setting up a magneto.) Assuming the Wassell is like the Pazon, once you do this you follow the directions for setting up the unit in the magneto replacement housing. Just looked at the Wassell instruction booklet and this is explained:

16 Set the engine at the fully advanced timing mark on the compression stroke. [Follow Slick's or other's instructions for how to do this.]
17 Fit the magnetic rotor in to the end of the camshaft in the contact housing using one of the bolts supplied (either BSF or UNF depending on model). Check that the bolt does not bottom on the thread. If it is too long, cut off a small amount of the thread. . . .

HTH

Got it, thanks to you both for the info.

After I wrote it I thought hmm, I may be on the wrong track and confusing myself. I was fresh off installing a Dyna S on my CB750 and was trying to visualize the Norton setup. The Dyna triggering magnet piece (as well as the centrifugal advance unit that it replaces) is positively located in relation to the crankshaft by a pin, and it got me wondering.

I'll read Slick's tutorial carefully and follow it. Step 12-14 focuses on position of the AAU (scratches head...) so after waking up and drinking some coffee I'll set it on the bike and try to get it sorted out better in my mind.

gpzkat said:

Got it, thanks to you both for the info.

After I wrote it I thought hmm, I may be on the wrong track and confusing myself. I was fresh off installing a Dyna S on my CB750 and was trying to visualize the Norton setup. The Dyna triggering magnet piece (as well as the centrifugal advance unit that it replaces) is positively located in relation to the crankshaft by a pin, and it got me wondering.

I'll read Slick's tutorial carefully and follow it. Step 12-14 focuses on position of the AAU (scratches head...) so after waking up and drinking some coffee I'll set it on the bike and try to get it sorted out better in my mind.

Click to expand...

As time goes on setting the timing on these old engines - where you have to find the full advanced timing degree setting using a degree wheel - becomes more and more of a black art known only to a select few. The old timers (bad sort of pun) just assume everyone knows how to do this. Even the instructions in the old manuals assume a certain level of familiarity with the concept.

Bodger said:

As time goes on setting the timing on these old engines - where you have to find the full advanced timing degree setting using a degree wheel - becomes more and more of a black art known only to a select few. The old timers (bad sort of pun) just assume everyone knows how to do this. Even the instructions in the old manuals assume a certain level of familiarity with the concept.

Click to expand...

I recently watched the process done with cigarette paper on YouTube. A Velo or Matchless, can't remember which. Between forums (i.e. social media) and videos online we are blessed these days. In the old days we had all sorts of wives tales and misinformation flowing about. Now with social media we can finally have the truth about things!

Oh, I also have read of troubles with the bottom magneto nut. Mine presented zero problem, it was quite easy. I will write up a little tutorial if I ever remember what I did to get it off. Actually I think it was just having all the bits separated, not fitted together in the frame.

gpzkat said:

OK well I concluded that I can't financially manage a ~$600 rebuild of the K2F magneto - I suspect a fair bit more once the full assessment is done. So I got a mini housing and Wassell MK2 setup for a bit more than half that. I can only research so much on this subject and pros/cons/opinions are endless. I don't want to open up any of that, I did what I did and will go with it.

The housing I got looks just like the Tri Spark one. It has a tapered shaft.

Click to expand...

Too late now, but I would have proposed the Matchless designed points housing available from Andover Norton (look up the "Desert Sledges"). The Mk2 version was fitted to the P11 and subsequently to the G/N15 series and Atlas & 650SS in the spring of 1967). IMHO it's a better design than the mini housing touted everywhere, and of course adds a bit of originality. It's probably more expensive than $300 altogether. If you're living in a mostly dry region it may not matter, but for me living at the coast of Norway, moisture sealing is an issue and the AMC unit is definately better in this regard. Having a straight shaft, the simple sprocket is a tight fit secured by a split pin. These units are rare but s/h samples do turn up on Evilbay from time to time.

- Knut

Thanks I'm a fair weather rider these days and am in southern California so there's plenty of sun. I am waiting on the crankshaft regrind still, it's been nearly 3 months due to a huge backlog. It's a good shop by all indications from those that know, just swamped. Once I have that I can put everything together, I have all sorts of new parts, pretty much end-to-end refresh. Sadly I have a delay due to my father's ill health, so I'm out of state indefinitely taking care of him, making his last days count.

Great help from people here on the forum!