Manual ignition timing Advance units. Where are they?

[Steveba10]

Hi, I’m doing a bit more with my mag converting it to electronic ignition.

I’m proposing to use the mag points to trigger an electronic unit.
The only mod I needed was to unsolder and secure the wire that leads to the low tension coil.
If I left it alone the low tension coil would have been in parallel to the points effectively shorting the points signal out.
This was easily done.

I then thought I’d slot the three mounting holes in the body to give my auto advance a bit of manual timing adjustment.
Again easily done with a small file.

I then, pleased with myself, got a bit carried away and started polishing the body and then disaster it slipped out of the vice and landed
on one of the mounting lugs breaking it off where I had weakened it by slotting.
Undeterred I got the tig out and welded ( puddled ) a new lug and drilled it.
But I didn’t slot it, my welded repair might not be strong enough. So no fine adjustment.

I then thought why don’t I do the simple thing and just look for a manual advance unit giving full control over ignition timing and also simplifying my proposed rev counter drive.

I’ve searched e-bay etc. and have found many K2F complete units and many more bare bodies.
Only a couple of housings for automatic advance were offered separately and none with the manual cable.

So where are all the manual cam/breaker housings?
Why so many bare bodies offered for sale.
It doesn’t seem to make sense.

I believe now it was only the sportier models that had the manual option.
When I first looked at mine I was surprised to see the auto advance, I thought all bikes of that era were manually adjusted.

I don’t really want to buy a complete mag just to get the manual cam housing.
So with no autojumbles and nothing advertised I suppose I’ll just have to wait for something to come along.

Any ideas anyone?
Steve.

[JulianS]

They do come up on ebay occasionally but can fetch £30-£40 or more for one which takes a screw on end cap.

You may need to drill extra fixing holes in the body. The auto type usually has 2 holes, the manual type needs 3.

[Ted_Flash]

See Lot 12 here:
https://www.a7a10.net/forum/index.php?topic=14889.0

[edboy]

hi steve,
i have a few spare manual end housings but  send a photo so i can match them up

[Joolstacho]

Don't forget that you need other items, not just the manual end casing.

Manual type cam-ring (they are different)
Lever
Cable
Adaptor / adjuster -(cable to mag body)
'Dolly'(?) -the part that fits onto the cable nipple that engages with the camring

[Steveba10]

Thank you for your replies.
To Julian, thank you I’ll just have to be patient and keep an eye on adverts.
To Ted, just what I need but need it in a smaller lot.
To Joolstacho, thank you I understand there is more needed, the lever and cable are easily available, my cam ring can be ground with the extra slot and if I can’t get hold of certain bits I’m very adapt at making some on the lathe.

To Edboy, thank you.
Searching images on the internet I see there are several differing designs over the years and applications.
I’ve added a photo of my case and housing.
If extra holes and tapping are required it should present no problem.
Thank you again,
Steve.

[Steveba10]

Hi Edboy,
I’ve just found a picture showing manual advance housings and associated bits.
I think the one I’m looking for is the one on the left as like mine it looks oblong.

The other two appear to me to be square but I may be wrong, I usually am.
It would be nice to know what fits what.
What do you think?
Steve.

[JulianS]

Left fits K2F, the type you need.

Middle fits magdyno and right fits square end K2F, K2FC and K2FR type. These will not fit your mag.

[Rex]

Liking manual ign timing I contemplated doing this when the A7 was first back on the road, but the variations in the bits needed plus the daft prices for end-caps etc meant that I gave up on the idea of collecting bits piece-meal and decided the best way was to buy a complete suitable mag and use that. In the meantime I became used to the ATD and haven't yet progresses it any further, but when  suitable complete mag turns up...

[edboy]

sorry as i am unable to help.
unfortunately the 3  spare manual end parts i have are the square type. no idea what they fit.

[bikerboy]

Why not just buy one of the electronic/mag bodies they are not that expensive?

[Steveba10]

Hi Edboy,
Thank you for taking the effort to look, I appreciate it.

Thanks also to Bikerboy and Rex, unless something turns up I can get the engine up and running with the auto mag.
I’d like manual control to fully retard for starting as I think my compression ratio is going to be high with the domed pistons I have.
I don’t have a feel for how hard these twins are to kick over.
I’ve got a burette for measuring the combustion volume so I can calculate the cr soon.

I’ve looked at the electronic ignition options and don’t rule them out, I just get greater satisfaction from working out my own solutions.
Steve.

[Steveba10]

Hi Edboy,
I’ve sent you pm’s about the possibility of sleeving the larger holes on a square ended housing, but I’m not sure they are being delivered as I cannot then find them in my sent folder.
Please let me know if you receive them as I suspect I’m doing something wrong.
Thanks,
Steve.

[MrShifta]

Hi Steve  I have just bought some boxes of bits and amongst them are 4 mags. K2F They are in a poor state and I am hoping to make one good one for my RR project.   There is a (brass ? ) mag end with the cam ring but I think you might have to make/find the bits to make it work.  It is clearly a manual end cap but I think it is square.  I will check it in the morning and try to send pictures.   

I do have a spare square mag case with an armature which needs a new slip ring.   you can have the manual end and the mag for £30 plus postage.

Regards

Barry

[Steveba10]

Hi Barry,
Thank you and I’ll look forward to seeing the photos.
I’m still trying to work out what fits what with regard to cam/ breaker housings.
It’s times like this that bike jumbles come in handy for making comparisons.
Hopefully things will return to normal in the new year.
Steve.