The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: Steveba10 on 01.10. 2020 13:48

Title: Manual ignition timing Advance units. Where are they?
Post by: Steveba10 on 01.10. 2020 13:48
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.









Title: Re: Manual ignition timing Advance units. Where are they?
Post by: JulianS on 01.10. 2020 15:50
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.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: Ted_Flash on 02.10. 2020 08:43
See Lot 12 here:
https://www.a7a10.net/forum/index.php?topic=14889.0
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: edboy on 02.10. 2020 20:51
hi steve,
i have a few spare manual end housings but  send a photo so i can match them up
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: Joolstacho on 03.10. 2020 00:30
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
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: Steveba10 on 03.10. 2020 09:35
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.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: Steveba10 on 03.10. 2020 16:01
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.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: JulianS on 03.10. 2020 16:46
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.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: Rex on 03.10. 2020 17:31
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...
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: edboy on 04.10. 2020 13:58
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.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: bikerboy on 04.10. 2020 14:29
Why not just buy one of the electronic/mag bodies they are not that expensive?
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: Steveba10 on 04.10. 2020 17:39
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.

Title: Re: Manual ignition timing Advance units. Where are they?
Post by: Steveba10 on 18.10. 2020 10:59
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.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: MrShifta on 25.10. 2020 22:33
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

Title: Re: Manual ignition timing Advance units. Where are they?
Post by: Steveba10 on 26.10. 2020 10:35
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.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: MrShifta on 26.10. 2020 12:28
Hi Steve, I don't think I can help you as the brass mag end which is for manual advance is the same as others on here with square mounting. I will post the pics anyway. as they may help somebody.  I am sure there is some poor soul desperate for a brass end, but as no-one seems to know what it is off it will go back into "stock".  The mag shown is parts only with a damaged slip ring.

Best of luck.

Barry
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: MrShifta on 26.10. 2020 12:42
Hi Steve, I am battling the system to post the pictures, Hopefully this time will work. 

Regards

Barry
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: MrShifta on 26.10. 2020 12:49
Sods law dictates that the one pic which was just for interest came through but not the ones of the brass end bit.

I will try again, sorry to mess you about.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: groily on 26.10. 2020 16:29
Sod is an active legal practitioner!
Looks like a BTH KC2 manual end housing to me.
The camring looks like a twin anyway - although it is pretty manky. Same housing on KC1 with single lobe cam. With the advance and retard on the left, it would provide slack cable advance on an anti-clockwise drive mag. The contact breaker end cover was a plate secured by the three screws that aren't equidistantly spaced. Cut-out by a springy strip kissing the head of the cb centre screw.
Not interchangeable with Lucas though, or not easily. But there will be someone who needs a manual one, so worth trying to sell it on I'd say.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: MrShifta on 27.10. 2020 11:29
Thanks mate, I had no idea so thanks for the info. I will put it on Ebay and see what happens. I am still sorting stuff out, I thought the mag and dynamo were good until I stripped them to find they had been in a bike fire.  Its not the bargain I thought it was.

Stay safe.

Barry

Title: Re: Manual ignition timing Advance units. Where are they?
Post by: Steveba10 on 27.10. 2020 19:00
Hi Barry,
Thanks for posting the pics.
I’ll keep looking, I’m not desperate as I have much to do on the bike before starting it up.
Steve.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: edboy on 29.10. 2020 22:36
hi steve ,
i ve posted your magneto part with hermes but its still at the drop off point with hundreds of other parcels.
i would give it until monday before delivery to your address at least.
Title: Re: Manual ignition timing Advance units. Where are they?
Post by: RDfella on 30.10. 2020 17:17
With hermes that'll be a monday in january - maybe.