Misc: Ignition Fitting a cutout cap to a Lucas K1F magneto on a Comet

[weevil.knievel]

Hi,

New member here, recently bought a 1950 Comet which I am currently pulling to bits

Whats the generally accepted method to retrofit a cutout switch to a Comet that has the Lucas K1F magneto?

This magneto has the bakelite/plastic points cap that is held in place centrally by a spring clip - its not a screw on cap.

I see lots of references on the internet to K2F cut out end caps but nothing specifically for the K1F so asking on here. I can also see metal screw-on type points caps with the cutout contact - but mine is not a screw on type. Or do I need to find and install a replacement magneto end plate with one with a screw thread, attach that which would allow me to use a screw on cap with cutout?

Or would one of these K2F end caps fit?

Classic Motorcycle Magneto Bakerlite End Cover for K2F Magneto OEM No 458619

Classic Motorcycle Bakerlite end cover for Lucas K2F magneto with cut out. Excellent QualityOEM: 458619,LU458619

www.classicbikepartscheshire.com

I did try the forum search but surprisingly nothing came up, and I cannot be the only person to have asked this question!

Regards,

Julian

 

[LoneStar]

That K2F end cap with cutout provision will work fine on a K1F.

 

[Trickymicky]

If you trawl through this, the K2F cut out cover (Part No 458619) is also the same part no fitted to a K1F.

https://brightsparkmagnetos.com/lib...le parts 1936-57/G09-23 Magnetos and ATDs.pdf

 

[Chris Launders]

The one in the bottom left of the top picture.

 

[weevil.knievel]

Hi everyone,

Many thanks for the answers - so the Lucas 458619 is the answer

Whats the best way to route the wire from the mag cover to the handlebars? Any recommendations?

Also any particular type of wire or sheathing or support clips/grommets recommended? For example some of the early Hondas like the CB160/CD/CB175 used a fabric covered wire sheath and slotted the wire between the cylinder barrel fins and had rubber support grommets.

Regards,

Julian

 

[LoneStar]

I don't think there are any special concerns for the wire to the kill switch. Note that for some reason, the connection at the cap is designed for a HT lead - but you're grounding the magneto primary, which is low-voltage, so there's no need for HT wire. I just use a stub of HT wire at the cap, connected to a normal wire, maybe 18 gauge, running up to the switch.

 

[bmetcalf]

I pack the opening with silicone seal to make the rain work harder to get inside the mag.

 

[Chris Launders]

I have a rubber boot for mine that fits the pickup and a "normal" wire, though where it came from in the last few decades I have no idea.

 

[bmetcalf]

Same here, I forgot about it. This looks like it: https://www.feked.com/magneto-cable-grommet.html

 

[b'knighted]

Normal procedure would have been to earth via a horn button. You could for greater security earth it via a key switch to leave it earthed when the bike is unattended.