Is there a trick to fitting the ATD on my ‘46 Series B with a newly rebuilt and installed KVF Magneto? I have the engine set at 35 degrees BTDC and the points set to open on the rear cylinder, and the ATD locked fully advanced. When I try to screw down the ATD nut it advances the magneto. Also, how tightly should I nip up the ATD nut. Thanks - Ben
Misc: Ignition Fitting ATD
- Thread starter Scout63
- Start date
G
Graham Smith
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1951 Vincent Rapide - Part 036: Ignition Timing
@Mike T 's journey with his 1951 Rapide.
www.vincentownersclub.co.uk
That is a special nut in the ATD unit. It has the internal 3/8 BSF RH thread and an external LH thread. This is so that it will extract the ATD from the taper. I have had occasion where the nut would engage the RH magneto thread before releasing the LH ATD thread. You pull it all up tight and think all is well, but the nut has not pulled the taper tight. You need to make sure the LH thread is disengaged, set the timing as you have described and start the RH thread, and then put a socket over the nut and give it a good tap to set the ATD on the taper, and the tighten the nut fully home, using a good feel for a TIGHT fit.
Hope that helps.
Hope that helps.
Another trick to help you is to take the earth brush and holder out and replace with a bolt with a smooth rounded end (should be 5/16 BSF), FINGER TIGHT ONLY, this will hold the armature in your desired position while you fit the ATD.
Make sure you remove it before turning the engine.
Make sure you remove it before turning the engine.
Thats clever, never to old to learn a new trick.
Like Robert says below, put a socket over the bolt head on the nut (has female threads) to push on the ATD body itself.
Also, I leave the wood peg that keeps it advanced in place until it is locked on the shaft.
G