Author Topic: Installing Thorspark ignition on my BSA A10 1956 GF  (Read 4332 times)

Online bsa-bill

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #15 on: 05.09. 2015 19:51 »
Quote
The mag. on the GF bike has been rebuilded 3 times since 1993.
On time by a Company in Sheffield cost 290 £

Now then, both my maggies were refurbished by a firm in Sheffield (not at the same time) Thing is both work well on he Flash but neither work well at all on the higher compression RGF, could it be that they are both happy with lower compression but not quite up to igniting Rockets.
Groilly kindly offered to put my maggie on his test rig some time ago, I should take up his offer soon.
I wont mention who the firm in Sheffield are (actually it runs in my mind that they no longer trade?) as there is one thing Groilly mentioned that I did not try and that is the clearance of the safety screws - could be relevant

Quote
My manners? I'm not crazy about them myself, but I don't like to see advice which I think is spurious.

Yep I get where your coming from. as for manners I have been told (buy SHMBO) my "WHAT" is close to a declaration of war, it's just the way it comes out really
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online beezermacc

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #16 on: 05.09. 2015 21:01 »
I see the old 'Mag v Electronic' argument has reared its ugly head again!
Priory Magnetos Ltd - A10 spares, magneto and dynamo refurbs. www.priorymagnetos.co.uk

Offline muskrat

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #17 on: 05.09. 2015 21:31 »
We love them (either) just the way we want them. I applaud anyone who has the expertise, time and patience to get the best out of a K2F.
 For me it's just flick the switch and go every time. It gives me time to fiddle with all the other stuff that needs fiddling.  *problem*
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
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Offline Viking

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #18 on: 05.09. 2015 21:36 »
I found that the mag. last longer if they are used on a regular basis.
Standing unused for some years is a killer...

Started the GF fitted with Thorspark today. First easy kick, no chok needed.
Fitted two new 6 volt sealed lead batteries on the bike. The bike can run for hours with out
charging.
We have another 61 SR , fitted with a Mag. That gave in 3 weeks ago...
I havde been surrounded by mag's giving up....  So it is time to move on

But my old SR with a RGS engine has a mag, and I am not changing it.

The pro and cons about mags was a hot "war" in the 50's , chilled down in the early 60's and as soon as the bikes got a propper generator "battery ignition" was king...

Mags pro: independend ignition, no need for a battery, the faster it spinnes the better and stronger a spark
Con: Hard to get equal timing on boath cylinders. Complex instrument needing specialist repair, hard to adjust the timing..

Battery sparks pro: Simpel system, strong starting spark, easy to adjust, easy to repair if faulty.
Con: Need a good power supply. Dynamo is not ideal for this....   The first battery ignition systems was not fantastic quality, used a distribitur, oh dear...

Don't get me wrong, I like the mag when they performing correct. The A10 is correct with it.
But some times you had to be practical..

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #19 on: 06.09. 2015 23:26 »
But my old SR with a RGS engine has a mag, and I am not changing it.

Why are you not changing it?
Priory Magnetos Ltd - A10 spares, magneto and dynamo refurbs. www.priorymagnetos.co.uk

Offline Viking

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #20 on: 07.09. 2015 10:24 »
Why not change from mag to Thorspark on my SR with RGS tuned engine ?
Because it is working fine... ( as good as a mag can). This bike is used more frequently, and has not lost its magnetism.
As long as it´s working I keep it.

If the mag on the GF was working, I continued with the mag.

I like the idea about "independent" ignition.    "Battery is flat and dynamo packed in, the engine will keep running and get you home"

But sending the mag to England, getting it reconditioned for hundreds of pounds and with short life span, and no use. Waiting for months to get the mag back from rebuilding,  is not a sport I will participate in.    
I used the GF with the Thorspark ignition a lot this weekend.  Starting is at “treat” very easy, hot or cold. It has never been so easy to start with a mag. It has a quick throttle response and pulls with more torque at low revs.

What about advance/retard with the Thorspark unit ?

I use an automatic advance unit on the bike.(even with the RGS engine. I don’t fancy fiddling with manual advance. The automatic units, work well. Adjust better than I can do myself with continually changing rpm. etc.)

Offline Topdad

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #21 on: 07.09. 2015 11:45 »
Has Musky says it's down to the individual , I've always used a maggy and I'm quite happy. Like CB mine refurbed approx. 12-13 yrs ago by mr Lindsey, still going strong (touch wood ) I put her to bed around the end of October and so far over the last 12 yrs or so when I remove the covers shes never taken more than 3 kicks to fire up. I'm first to admit I don't ride as quickly as some do (50-60mph) ,but thats down to knowing my limitations not the bikes which runs really well with a good solid tickover and good response even 2 up. I particularly like being able to get home even if the battery has given up the ghost ,which back in the day they did frequently .
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Offline duTch

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #22 on: 07.09. 2015 12:19 »

 I had my maggie refurbed circa '95ish, used it a couple of times only, then it sat redundant from at least '98 until 2013, and has been running fine since then- use it most days generally starts first kick except when I get complacent, and lazy *bash*
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Online chaterlea25

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #23 on: 07.09. 2015 18:14 »
Hi All,
If  a magneto has been rebuilt properly and as importantly the correct capacitor (condenser) fitted
It should last almost indefinitely, with just routine servicing,
I have mags which were rebuilt 30 odd years ago and are still fine
With the introduction of modern insulating materials the windings should no longer detioriate with age
The old shellac insulating absorbed moisture
In recent times there have been problems with the quality of slip rings and pickups originating from "God knows where"
Old even NOS capacitors die because of age,
I have had to replace several capacitors on "rebuilt" mags as they had failed ! they were not fit for purpose in the first place *razz* *razz*
Some pattern points are equally crap!!!

My 2 cents worth
John










1961 Super Rocket
1963 RGS (ongoing)

Offline Viking

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #24 on: 07.09. 2015 20:21 »
I agree, should work.

They have all been rebuild by SRM.
Rewound and modern capacitor fitted, cam ring reground, new Lucas contact etc.

It gave a spark, a weak one, But it is too weak to ignite the fuel..

Did a ride on the bike today again.  Extreemly easy starting. No choke needed..
Did a run with full light for hours.. No problems...

Good old Lucas parts, same good old quality as Layland
http://youtu.be/b9ztUlve9jc


Offline muskrat

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #25 on: 07.09. 2015 21:07 »
I will put a word in for the K2F. I had one rebuilt by Peter Scott in Sydney about 30 years ago. It ran the plunger for about 10 years, it was giving trouble at the end. I bought a new Boyer for the racer and put the old Boyer on the plunger. Fast forward 20 years and I plucked the K2F out of the box. I set it up on the bench and fitted spark plugs. First spin with my fingers produced a nice spark. Then hooked it up to the drill and it was giving beautiful sparks. It was then that I noticed why it was giving me trouble all those years earlier. The shaft was bent. I must have installed the auto advance unit a bit scewiff (don't know how) and running it like that bent the shaft.  *bash*
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Online edboy

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #26 on: 07.09. 2015 21:55 »
started up the a10  yesterday with a rebuilt off the shelf magneto. it was rebuilt 20 years ago by the old boy whose surname was day living in slough so the magnetism argument i think is a red herring. however i had trouble starting it until i changed the automatic advance to a more worn one that was happier to return when bolted to the mag. i would be happy to fit thorostart as it looks a good product but consider the old bsa auto adv unit the weak link for mag or thorospark. luckily i have a few spare ones i will strip and rebuild .

Offline Viking

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #27 on: 08.09. 2015 08:15 »
Getting at spark out of a mag, is not hard.
Getting a spark that can perform correct under compression pressure and ignite gasoline correct is a harder matter.

I have had a heap of old mag from boat engines. They give a fine spark on the bench. Fitted to the engine they can´t perform..
Low compression is ok, high compression is much more difficult..

Can you remember the old type spark pluck tester, in garages  ?
After grit blasting the plucks, they were tested under pressure to see if they could perform.

So getting at spark form an old mag. In free nature, is not difficult.

The worst enemy of magnets is: Vibration and heat.

They are not exposed to that laying idle in the workshop…

http://www.vehicle-electrical-rewinds.co.uk/magneto-common-faults.html

A good article about magnetos:
http://www.realclassic.co.uk/techfiles/magneto0912.html


Last night I did a good long drive with the GF A10, fitted with Thorspark ignition.   ummm.   good strong pulling power from low down.  Easy starting and smouth running.

     

Offline Topdad

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #28 on: 08.09. 2015 10:15 »
Hi Viking,
     
         "    Last night I did a good long drive with the GF A10, fitted with Thorspark ignition.   ummm.   good strong pulling power from low down.  Easy starting and smouth running"

You descriping my maggy equipped GF ?? ,Bob
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Online groily

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Re: Installing Thorspark ignition on my BSA A10 1956 GF
« Reply #29 on: 08.09. 2015 11:14 »
If people don't feel comfortable with mags, fair enough, no reason why everyone should, especially if they're happy with their charging system or inves tin a modern BTH independent spark generator.
But there is no reason at all why a decent mag won't fire a high compression engine. Yes, on methanol at 14:1 or something there could be some HT insulation issues maybe, but for anything we need they should be fine. I haven't noticed modern fuel making a jot or tittle's worth of difference on my own bikes.

All the weaknesses mentioned exist, of course they do, but so do the strengths. Firing intervals can be got right, ATDs can work, the guts can last for years and years. Magnetism doesn't just disappear on most post-war Lucas instruments and is extremely rarely the cause of failure.
Some of the electronic options don't address all the weaknesses, can introduce new possible points of failure and also steal your storage space.

It's all a question of where you feel happiest carrying the risk (and/or whether you want 'original' I suppose). I don't care about original myself very much, looking first for 'reliable' to support quite high mileages. For me, mag + dynamo + DVR2, or alternator + decent solid state regulator/rectifier + mag = 'reliable'. For others, 'reliable' may = Alton alternator/ good E3L and electronic sparks or Lucas alternator + coil etc etc.

What the hell - as long as we're out there on the road, doesn't really matter does it?
Bill