The Knowledge - Velocette Owners Club

to the fibre drive gear as there is nothing to "time" between these two devices. Since the magdyno
needs to have the outer cover in place when installed, the holes for above mentioned "U" shaped
keeper could not possibly be used to restrict the magneto from turning once the magdyno is mounted 4
degrees BTDC sound a bit late to this reader. Is it possible you are setting ignition time with the ATU
bob weights in the "at rest" position? As most engines spend the bulk of their working time at full
advance, there is great advantage in always setting ignition at full advance, I.E. bob weights wedged in
the "out" position.
#3446 I too recently faced the problem of trying to stop the mag from rotating while setting the ignition
on a '46/47 MAC which I was bought for Christmas! (same age as me). I simply held the contact
breaker fixing bolt and tightened as much as I dared; it has covered a few miles since with no problem.
However, the timing was approximately 35 degrees too far advanced when I had checked it, so it may
well slip again. If only I had the sense to solicit advice from this forum at the time ( thanks "Doctor" ). I
can confirm that the 4 degrees before TDC fully retarded is correct according to the manual. The
advance-retard mechanism on these machines does not use conventional bob weights.
L #3470 --Re topping batteries. I use a gel battery off a modern bike, no acid to spoil paintwork
while breathing and no need to top up as its sealed after the initial filling.
#3472 I don't know the reason why but these modern gel batteries are not recommended for bikes with
magnetos/dynamos, read it recently in one of the monthly classic mags, would be interesting to know
why as I know many that do use them without problems..
#3493 The reason is that the old electrotechnical regulators were set too high in volts. With a normal
battery this just meant they gassed off a bit, so you had to top them up with water once in a while. Gel
batteries can't be topped up, so if you overcharge them they lose water and eventually don't work.
Electronic regulators can be set accurately below the voltage at which this happens, so no problems -
when did you last top up the battery in your car?
L #3476 I'm planning on using wheel bearing/high temp grease on the magneto bearings, any
suggestions of a better lubricant? Also, is the points cam follower oil wick effective or should I use light
grease there as well?
#3483 Almost any NLGI grade 2 grease specified for disk brake applications should be fine. The CB
end will definitely benefit from both oil and a dab of Bosch or comparable contact breaker grease,
especially of the ring cam still has both felts still in place. If the bike gets ridden in the rain, you might
want to use boat trailer (water resistant) grease on the control spring and plunger, and a fresh rubber
boot (Lucas #458731) to keep things dry.
#3484 Only one wick hole in my mag cam...it has the auto advance/destruct mechanism. I'll replace the
wick. Do you think it's advisable to put some kind of removable coating on the armature windings? I've
read where the shellac eventually turns to goo, deposits itself on the armature, and locks up the
magneto. I appreciate the help.
#3487 Look carefully, is there a round felt in the hole, or just a rectangular felt in the recess at the
bottom of the mag housing. Unless both are present, there is no way capillary action will "wick" (pun
intended) the oil thru the cam ring and lubricate the breaker. As to the armature, your question leads
me to believe this armature has not been rewound. If that is the case, I trust you have a plan for hauling
your bike back home when the magneto fails. They all do! The 50 year old windings will fail sooner or
later, and the ancient capacitor will fail to restart the bike when the magneto is hot. This always occurs
when you have just come out from a store after a brief ride, some fellow is admiring your bike, and tells
you he had one in back in 19XX, and wishes he still had it. He will tell you about his travels while you
get red in the face trying to start yours. Bite the bullet and get the mag rewound.
#3488 Anything you put on might do the same - specially if it's 'removable' - what did you have in mind?
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