What does this F indicate

[Tommo]

I'm looking for ideas as to what the "F" stamped on the edge of the mag platform of this 1925 J model motor indicates.
A couple of us here in N.Z have a theory but I'm interested in any thoughts other people may have before revealing what we think as I don't want our thoughts clouding the issue.
We do know of two other crankcase sets here in N.Z. that are marked in exactly the same way, another 1925 set and a 1926 set.
All three sets have the correct matching belly numbers and in our opinion are factory applied.
Lets hear your thoughts Please!
Tommo1925 J with F3.JPG1925 J with F 2.JPG

[Jerry Wieland]

Tommo I have a couple of 1925 engines. I will look and see if mine have it. I see these stamping on HD aluminum casting and I always assumed they were Inspectors/Quality Control marks but I do not know for sure.

Jerry

[T. Cotten]

For what its worth, Folks,...

I have a Millers Falls stamp just like it!

(Indian used them for some VINs...)

....Cotten

[exeric]

My only observation is the inner timing gear case looks to be for a magneto, but I don't see the usual 2 magneto mounting holes. Could that case have been intended for a British, or Euro mag/dyno unit? . . .

[Tommo]

Here's what we think may have happened.
Come the mid 1920's demand for magneto equipted H.D's was fairly small so we think it's possible that if the factory got an order for a mag model and no FE's were available for dispatch a JE was converted to mag ignition and the platform base stamped with a "F" to denote the change.
I think we then need to consider how late in the 1925 production year this motor is and that the factory was using up what was around without having to manufacture another bike.
My guess it's very near the end of the 1925 production period and according to it's known history is supposed to have been a mag model all it's life.
To me all the signs point that way with the big question being, "Did it leave the factory that way?"
If it did that may explain the mystery "F" but if it didn't we're back to the first question I posted."What does that "F" signify

[Tommo]

Eric
As far as I'm aware the mag model inner timing cases do not have the two screw holes for the screws that hold the generator to the timing case.
No mags I'm aware of have holes for screws to attach them to a HD timing case

[exeric]

I've seen the 2 holes on Excelsiors, and my Merkel that line up with tapped holes in a Bosch mag. I think it was to pull the magneto into a gear cover gasket to minimize oil leaks.

[Tommo]

Does nobody have any thoughts on this issue?
What would happen if this motorcycle turned up for judging with a JE engine number and a mag fitted?
Eric, I've looked at all my ZEV Bosch mags, 6 in total and none are drilled to take screws to secure them to the timing case.
I'm not saying they don't exist, I'm just saying I've never seen any.
I've also looked at all the HD mag model timing cases I have, 6 in total and none of them are drilled either.
This may be an Excelsior thing and that's a make I know very little about so please don't take offence as to my comments I'm just trying to get some clarity as to whether or not JE's were fitted with mags at the factory.

[exeric]

You're correct, Tommo, I looked at a picture of my '16 J timing case and it doesn't have holes at the magneto opening. My Ex, and Merkel do, but that doesn't mean they weren't drilled by some genius 100 years ago I always pay close attention to your observations, and comments, Peter.

[MMasa]

Tommo
I still have a few 1925 sets of cases and bottom ends that I got from the Coopers down in Christchurch years back. I’ll take a look at those and report back.
Mark Masa

[Tommo]

Closer inspection also revealed a "F" stamped on the top face of the mag platform and a phone call to Steve revealed that his 1925 set was marked the same.
Clean up the 1926 set and once again we have a "F" on the edge and on the platform.
HD didn't put markings on their products unless there was a reason for it.
The marking of cylinder base flanges with numbers and letters is a good example of this.
The HD factory wouldn't need to remove the engine of an assembled electric model to convert it to magneto ignition.
Remove the lights, generator, switch box, wiring and battery box and install the mag bits and pieces along with a toolbox and you're done.
All the bits you're removed would be current and easily used up.
What you would put on is parts that were almost redundant and not in very high demand.
What a good way to use up your old stock but this still brings us back to the original question.
Did the factory do this?

[Tom Wilcock]

I have several Bosh 42 degree (Indian) magnetos and one 45 Bosh magneto with the 2 holes in the drive end. I have several Bosh single cylinder magnetos with the holes as well. Hedstrom Indians as well as other makes with separate timing cases used these holes to attach the timing case to the magneto.
Tom

[Tommo]

If I turned up to AMCA judging with this JE with a mag fitted what would be the reaction of the judges?

[T. Cotten]

If I turned up to AMCA judging with this JE with a mag fitted what would be the reaction of the judges?

It better not be anything but awe, Tommo!

Apparent exceptions are as important as the apparent 'rules', and only your experienced eye (and sharing it to this valuable forum) has saved it for posterity.

....Cotten

[MMasa]

Tommo
i looked at 4 sets of matched 1925 engine cases, Two are F models to begin with and two are JE models. The areas on the F models where yours is stamped with an F are blank. One of the JE’s is also blank in those areas. The second JE has the letter C stamped on the edge and top of the magneto / generator mount.
All of these came from New Zealand (Jones Brothers)
The plot thickens.
Mark Masa