This listing is for the proper BTH Competion type (i.e. TT or Dirt Track type competion magneto) PLATINUM BTH KD1 Contact Breaker Points Set
These are the correct platinum contact breakers, as were originally fitted to genuine competition KD1 magnetos, and the key differentiatior between the racing version and the standard version. They are now almost impossible to obtain - and we only rarely have them in stock
Update July 2024 - My specialist UK magneto parts supplier has finally made one more small batch of these genuine (precious metal) platinum points sets. I know the price is expensive (as the old saying goes 'if you need to ask how much they cost, you probably cannot afford them!') - but these are the genuine article, and I think - possibly the last time they will be available, as my UK manufacturer has now pretty much retired. I only have a handful of sets available . . . and once they are gone they are really gone!
These are sold as a pair - i.e. two threaded points, one with a locknut - which is the one used to adjust the points gap (normally quoted as 12 thou).
BTH Magnetos - Further Background, and difference between Std and Competition Magneto Types:
BTH magnetos were used by many motorcycle marques, and are widely regarded as being the best quality of all the motorcycle magneto manufacturers - giving the best spark and best overall reliability.
From the late 1920s through to the early 1950's Norton competition motorcycles were most commonly fitted with BTH competition magnetos (although Lucas competition magnetos were sometimes fitted instead, on request. And of course Norton road models were almost universally fitted with Lucas MagDyno units).
We are often asked - what differentiated a 'Competition' BTH magneto from a standard magneto, and how can that be identified?: Well in the case of single cylinder models - the competition magneto were normally the BTH KD1 type - but if it is a genuine competition type - it will normally have an additional brass plate riveted to the body on the opposite side to the Serial No/Model Plate, that says either 'TT Magneto' or 'Dirt Track'. The BTH KD1 model was also made in non-competition type, as well as the similar KH1 model. They were made in both (triangular 3 point) flange fitting and platform fitting - it being the platform fitting type used on SOHC and early DOHC Norton models (and with Arthur Carroll engines - only 3 studs were used, because of the crankcase mount casting). It should be noted that the Serial Number of the competition models could also be used to help identify the competition type, but this seems less conclusive.
As far as the internal differences between a TT/Dirt Track competition type and a standard type: Well talking to most older enthusiasts and magneto specialists in the know - 2 key differences normally get mentioned: First - there is a view that the armature windings on the competition type may have been slightly different (more winding/more robust? - not sure). However, as most magnetos are now at least 60-70 years old - and re-winding of magneto's is considered an almost essential part of a reliable rebuild .. . this is hardly relevent any more!
And of course the other difference - was that the genuine competition type magnetos were normally fitted with precious metal 'Platinum tipped' points, rather than the normal tungsten points. Again, it should be noted that points do eventually wear and get replaced - so it is highly likely that most original TT or Dirt Track have now had their original points replaced - and as Platinum points were always very expensive (and not easily available for many years) - it is very common to find even competition magnetos fitted with 'standard' tungsten points. Normally platinum points can be identified from tungsten type, as the points (tips) themselves are slightly smaller than Tungsten points (as can be seen in our accompanyning photos).
As platinum points are now almost unobtainable, and of course very expensive (see our 0185B - but we only get them made occasionally in very small quantities) - it is almost universal procedure now to fit good quality Tungsten tipped points instead, when rebuilding a magneto - and fitting good quality points such as these will give much better results than original worn or corroded points