Wanted, Lucas 42248E Mag. Needs to be complete, doesn't have to spark.

[GordoninNC]

It's in the title.

I'm in search of a Lucas 42248E Magneto.   Non sparking but complete for use as a learning tool.

Would consider a complete working mag if that's all I can find.

Thanks in advance,  Gordon in NC, USA

[groily]

Is there any particular reason why you are looking for that very specific version if it's just a 'learning tool' you want?
You can see the variations up to '57 in the Lucas Parts Lists for 1936 - 1957, pages G12 to G16 (with illustrations).
For identification purposes if you haven't got one to compare, 42248 (and 42248 A - D too) is anti-clockwise drive with a fixed camring, 45° angled clip-on HT pick-ups and bakelite points cover with wire off for the engine Stop.

The id label on a swap meet find may not state the whole truth though - many mags have had bits changed over the years

[CheeserBeezer]

I'm knee-deep in them but postage to USA is prohibitive. I agree with Groily, any K2F with clip-on pickups should suffice. Just make sure it's a/c rotation at the drive end and not for a 'V' twin, then it should work on an A10 if you get it going. If you see anything on ebay, send the link to the forum and we can check it's what you need.

[groily]

It might be worth trying Skip Brolund of Skip's Old Bikes across in Ohio - he will also have a pile of these things I'm pretty sure  . . .

[Swarfcut]

Magneto numbers can be simplified in that the number indicates the factory build specification  of the complete unit. So even a change from a spring washer to a plain washer would result in a different number or suffix letter on what was the same basic unit.
  Lucas, as a major supplier, found their product on numerous motorcycle Marques, all requiring slight variation on the magneto to suit a particular machine. So one that started life on an AJS or Triumph Twin can end up on a BSA. So for example bell push, clip on or screw on cut out cap magnetos will have three different numbers, but as regards fitment, complete magnetos all interchange. "Proper" BSA K2F magneto has a machined flat on the body to allow greater clearance at the back edge of the cylinder barrel flange. Bet you folks go and have a look.

 Swarfy

[GordoninNC]

Thank you all for the quick replies.

I have (long story, I'll not share right now) a running 1952 BSA A10 Plunger with a box mounted.   I'm a BSA unit singles guy....I have some unit twins but this A10 is my first (and probably last) pre unit.   I know absolutely nothing about a mag.  Because the motorcycle has a box mounted on the LEFT side (part of that long story) I really can't "see" the mag well enough to work on it (yet).

I'm wanting a mag I can have on the bench so I can familiarize myself with all the bits before I start trying to do regular service on the mag.

The mag's label is missing.  So I have no clue exactly what mag is on there but thought it a good idea to start the search for one that was supposedly originally fitted to the motorcycle.

My first time posting so Im not sure how the photo's attach but if one did........this is the type of mag that's on my motorcycle...at least the best I can tell.  100% sure the points cover is that type.

   

[groily]

Thanks for the explanation Gordon! Makes good sense. Hope you get to like pre-units enough to hang on to at least this one.

Your '52 A10 would have had the 42248E on it, yes.

Just for completeness, if anyone cares, the mags used on 7s and 10s up to '57 were (Lucas says anyway):

A7 '47-'50 (mid year) and A10 to mid-year 1950: 42174A (fixed cam, ATD) Late 1950, it was 42174B/D.
A7 & GF from then on to '57: 42248E (fixed & ATD)
A7 ST & SS, and A10 RR 42263D/E (manual AR)

After that date, not sure what versions Lucas think went on them.

Nor do I know, but C-B probably does, whether all mags with those IDs had chamfers on; nor who put them there - Lucas or Small Heath. And then there are the ones which have obviously been milled 'DIY'  . . .

We've all seen virtually every version of K2F and K2FC on all manner of parallel twins over the years, and on my own very impure A10 I ran with whatever I felt like at the time  . . . as long as it had an 18mm bearing on the drive end, not the earlier 15mm one.

Digression on shaft dia: The Parts Lists may contain the odd error as there's at least one combination listed that looks dodgy to me (for K2F 42248A/D in fact), but I think the 'big shaft' combination is Armature part # 459004, with oil seal 459002, as opposed to 458333 & 459031. If that's correct, 42248E has the larger shaft.
In any case, no 15mm armatures were fitted after the "early '50s" at the latest - and some of those small ones have been modified to take the larger bits. Dave Lindsley did a good few and had a jig set up to bore the bodies to suit, I did a couple back when as laborious one-offs, and I'd guess most repairers have too.
They're easy enough to measure, should the above interpretation be incorrect. I've only occasionally seen broken 18mm drive ends but have often seen the smaller ones with loose / drunken or busted ends. Hence avoiding the latter on my own machines. I have a suspicion that eccentric drive trains are what probably causes breakage, which reinforces the thought that timing gear trains need careful assembly and checking in multiple positions before covers are slapped back on! I've heard quite a dew times that Lucas went to the stronger shafts following the failure of the mag on an AJS Porcupine on the I o Man whenevr it was, but whether that's true or just a bar-room myth I dunno  . . . .

[GordoninNC]

groily wrote "Hope you get to like pre-units enough to hang on to at least this one."

This A10 belonged to our good friend Bryan Jones (RIP) in the UK.   I'm honored to be it's caretaker for now.  I have no plans on letting it go.....until it's my turn.

I took groily's advice and contacted Skip Brolund and he's going to help me out.  WHAT A NICE FELLOW he is.   

You can see with the "box" mounted on the left side.....it's hard to get to the mag.  I want to "learn" how the general service bits look and work before I dive in there to service the mag.  I plan on showing the rig at several events this year and it needs to run like Bryan had it.  BTW....right now it runs fine.....I need to keep it that way.

 

Thanks for all the help fellows.

[Rex]

He had the Net psuedonym of "aboxontheside".

[GordoninNC]

He had the Net psuedonym of "aboxontheside".

He really was a special person......one of the nicest person I had the honor of knowing.

There's a written history that came with the A10.  Bryan was the second owner.   As long as I have it........it'll stay just as it is with all it's bumps and bruises. 

I owe it to his memory to keep it running in good order.  Already tried to stop the oil leaks at the rocker covers.....with "some" success.  Changing the gasket at the faring to windshield.   Been riding it around but I'm having trouble getting used to the box on
the left side.