K2FC Magneto - Points Checking

[Brucie64]

Hello

Advice needed here (Again) for a Newbie.

Just before I strap my newly refurbished tank on my bike and try to start it for my first time I thought I would be clever and check the points for correct clearance, pitting etc. My brand spanking new manual says the points are hiding behind the magneto's end cap. This is where I ended up being not so clever and fell at what seems the first hurdle (Please view photo).

As I try to unscrew the end cap, a little breather type protrubence at the bottom of the end cap hits the long magneto mounting bolt at the bottom. I then thought I must have to take out the long mounting bolt in order to get the end cap off but then thought as space isn't at a premium in that area if I unscrew the offending long bolt I may never get back in again without taking off the primary chain case off.

Surely all this hassle can't be right just to check the points (can it?  ). Am I missing something obvious and making what should be a simple job very complicated?

[LJ.]

Hi Bruce! I've not seen an end cap like that on a magneto before... I'm wondering if the internals are electronic?? As for the long bolt... You okay to undo this as it only holds the magneto in place, there are two other bolts that do the same job and will hold the maggie in place while the longer one is out. It is easy to remove and replace, nothing will fall off or cause further complications. Good luck and let us know how you get on!

[dpaddock]

Congratulations, Brucie, on you're owning a 1957 Spitfire! I have one, also. You have one of only 285 made (approximately; factory records are a bit imprecise). Most of the 1958's and all subsequent A10 Spitfires were built on the standard (non-Gold Star) A10 frame. Unit Spitfires are, well, not the same . . .Keep it under lock and key.

Removing the mag cover is easy; there are at least two ways to proceed. Firstly, you can take away the "long bolt" (it's actually a "nut") and unscrew the mag cover. Or, you can loosen the nut that appears to hold that funny-looking post to the cover, thereby letting the breather tube rotate freely as you unscrew the cover.

Let us know what that post does - it's not a Lucas thing, I'm sure.

David

[trevinoz]

Gents, that "post" is a breather. It is a Lucas part and was fitted to some K2FC magnetos.
Someone may know why a breather was necessary but I don't.
Trev.

[LJ.]

The breather... If it is such, is most weird as it has ridges for pushing on a rubber tube by the looks of it?? Normal maggies usually only have a small hole on the underside and even those small breather holes... I dont know why they are needed, apparantly they are crucial to the functioning of the magneto so its always important to ensure they are clear.

[G/F DAVE]

This type of end cap was fitted to K2FC competetion magnetos and is normally fitted to TRIUMPH pre-unit bikes. The end cap has a breather as the magneto body of a K2FC does not have the breather hole drilling at the bottom as on standard K2F magnetos. These type of caps are also known as WADER hence the breather for competetion work when bikes where in contact with water. You could swap the centre cap (the breather part) for a the black plastic centre type as fitted to standard K2F then you undo cap easily.Personally I would leave well alone and just slacken the breather part to undo cap. G/F DAVE

[Brucie64]

Good News, the end cover "which ever type it is" is now off and I can see my points. just got to now find me feeler gauges!

On a different note....
I noticed after I finally got the end cap off that the manual advance/retard seems to be working in the opposite sense to what I thought is the norm. When I pull the lever back on the left hand side of the bars (away from it's normal rest position) i.e. towards me sitting on the bike, the advance/retard ring moves clockwise  . I thought it should be moving anti-clockwise to advance the ignition?

There seems to be an arrow on the description plate of the magneto and it seems to be pointing in the same direction as the advance/retard direction. Is this what the arrow is telling me?

Also thanks G/F dave for your detailed posting ref these type of competition mag end covers normally fitted to Triumphs. Does anyone know from the serial number where and what it's from? (K2FC 1159 423680)

[LJ.]

Im not too sure about the K2FC magnetos, but this is something to do with Slack and tight wire opperation, I'm only familier with the singles type maggies concerning this.... But! I bet it wont be long before this thread diverts to interests in your gearbox with that number SGT2 what ever that is? Time for us to see some complete bike photos I think Bruce! 

[Brucie64]

Hi LJ

Many Thanks for your post, I believe the markings on my gearbox are SCT2 which I have been told stand for Scrambler gearbox with Torrison needle bearings on both the main and lay gearbox shafts

[trevinoz]

Bruce, that number I would guess is 42368D. and was manufactured in November 1959. It was most likely fitted to a Triumph Trophy, U.S. model.
The same magneto was fitted to U.S. Nortons in the early 60's.
Your advance cable is correct. The magneto rotation viewed from the points end is clock-wise. As you pull back on the lever, the cam rotates clock-wise thus giving a later points opening, i.e. retarded.
 Trev.

[Triton Thrasher]

Magnetos have breathers to disperse the buildup of ozone from points arcing. Ozone conducts more easily than air and could conduct the HT to earth.

I think it might be corrosive too.