Twin Magneto

b.l.hayward@tesco.net

Forum User
Non-VOC Member
Ok...time for an update - sorry for the delay in posting but life got in the way!
Decided to give Dave Lyndsley a call and he gave me a couple of bits of useful info:
1. The only real difference between a KVF and the more ubiquitous K2F is the cam ring which operates the contact breaker. The armature, winding, contacts and slip ring are all the same. It's just the asymetrical positioning of the lobes on the KVF cam ring that causes the spark to occur at the right time for the V (the position of the standard slip ring contacts means that the pick-up brush is sitting on the contacts even though the contact breaker opens earlier for No.2). Hence why No.2 spark is weaker - the armature turns through fewer degrees of rotation.
2. If the cam lobes/end cap have inadvertently been set up 180 deg out then it's perfectly feasible to time No.1 on the TOP lobe - as long as the timing for No.2 is then where it should be.
My KVF has been modded for manual A/R and the slot in the rear of the cam ring to move it with the cable means the cam ring can only go in one way. Plus the position of the A/R cable abutment means that the end cap cannot be turned thru' 180 deg.
So I timed No.1 on the top lobe and checked No.2 timing - spot on! Petrol in the tank, flood the 276's, retard a tad, hefty swing and the beast burst into life for the first time since 1970, at least! MoT'd last Wednesday and sent of for my historic vehicle (free) road tax yesterday - bliss!
Many thanks to all.
Brian
 

Len Matthews

Well Known and Active Forum User
VOC Member
Another option would be to dispense with the manual advance end casting, fit an automatic (plain) one and fit an ATD, Good enough for the makers,good enough for me!:)
 

b.l.hayward@tesco.net

Forum User
Non-VOC Member
Er....why would I want to tear down something which is now working fine? - I gave up creating work for no good reason MANY years ago. Besides , my twin 5 inch clocks on top of the forks look really nice! :eek:)
 

Len Matthews

Well Known and Active Forum User
VOC Member
Glad to read that you've solved your problems. Come to think of it, fitting an ATD would be hassle, pipes off, timing cover off,etc. not to mention expense!
Bad suggestion, sorry.:eek:
 
Top