K2F auto A/R to manual A/R conversion

[terryg]

What about an electronic tacho?  Wasn't there some discussion on here recently, including magneto ignition?  Sorry, too lazy to use the search just now...

[pdg]

Yes. The ones I've seen require 12V so it is something I could go for with a change from 6V.

[terryg]

A neat little 6-12V DC-DC converter, tucked in somewhere?

[pdg]

Does anyone know if the Gold Star tacho+speedo mounting plate that fits across the handlebar yoke is a standard fit - e.g. is it likely to fit an A7 long stroke or did BSA produce different yokes for different bikes. The item I'm thinking of is shown at http://www.classicbikepartscheshire.com/speedometer-tachometer-c41/speedo-mounting-spares-c42/classic-motorcycle-bsa-speedo-tacho-mounting-bracket-p515 but this has the cut out for the ignition key that clearly I don't have.

[Topdad]

I beleive that all the plunger and swinging arm yokes and forks interchange can't help re the longstroke though but BSA were so mean about changing things I be surprised if it were diferent. The key cutaway is gfor a steering lock not ign key , goldies were mag fitted as well as ours ,regards BobH

[pdg]

A neat little 6-12V DC-DC converter, tucked in somewhere?

What a lovely idea - very smart. I'll look into it.

[pdg]

I beleive that all the plunger and swinging arm yokes and forks interchange can't help re the longstroke though but BSA were so mean about changing things I be surprised if it were diferent. The key cutaway is gfor a steering lock not ign key , goldies were mag fitted as well as ours ,regards BobH

Many thanks. I'll give it a go.

[wilko]

here you go.  http://www.ebay.com.au/itm/221207451815?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

[wilko]

And.....http://www.ebay.com.au/itm/1960s-70s-Vintage-BSA-Triumph-Norton-S424-A7-A10-outer-engine-timing-cover-3-/231312737313?pt=Motorcycles_Parts_Accessories&hash=item35db504421

[pdg]

Many thanks.
Does the K2F mag send a sacrificial spark to each cylinder (e.g. sparks twice at each cylinder every 4 revolutions) or does it send just one spark to each cylinder every 4 revolutions?

Regards, Peter.

[duTch]

Does the K2F mag send a sacrificial spark to each cylinder (e.g. sparks twice at each cylinder every 4 revolutions) or does it send just one spark to each cylinder every 4 revolutions?

 Well if you think about it, the cam spins half speed of the crank, and there's only one brass strip in the slip-ring- so that'd have to mean something..?

[pdg]

Sounds like both plugs spark every 2 revolutions, meaning a sacrificial spark. 

[Triton Thrasher]

Sounds like both plugs spark every 2 revolutions, meaning a sacrificial spark. 

They don't.

[bsa-bill]

Sounds like both plugs spark every 2 revolutions,

Hi pdg
They do but not together,
each revolution of the magneto produces two sparks, 180degrees apart, in that time the crank has revolved twice completing four strokes in each cylinder who's compression strokes are 180 degrees apart, so no spare spark to be had.
I know the more you think about this one the more the big bang theory makes sense

[pdg]

Sounds like both plugs spark every 2 revolutions,

Hi pdg
They do but not together,
each revolution of the magneto produces two sparks, 180degrees apart, in that time the crank has revolved twice completing four strokes in each cylinder who's compression strokes are 180 degrees apart, so no spare spark to be had.
I know the more you think about this one the more the big bang theory makes sense

Many thanks for the clarification.
Regards, Peter.