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Vincent Motorcycle Electrics:

Alton generator testing - Feb 2015 from K17 So cal - S. O. SEZ by Dave Marshall -      I looked into my charging problem on my Comet this month.  I contacted the maker, Alton, and they gave me the following instructions on checking the Alton for output:
Do not forget to check for ground/earthing issues.  Then please do the following basic controls using a multimeter (if not already done):

       Two static tests (engine off):
[1-1] Test for continuity between the 2 wires from the AC generator.  There should be CONTINUITY between those wires.
[1-2] Test for continuity between one (or the other) wire from the AC generator and the Alton body.  There should be NO continuity.
       Two dynamic tests (engine running):
[2-1] Disconnect the AC generator from the regulator.  Start engine.  Check AC voltage between the 2 wires from the AC generator.  This voltage should reach 20-22 volts AC as soon as you rev up engine (let's say at a high idling rpm).
[2-2] Connect the regulator to the AC generator with everything as it should be.  Start engine.  Check DC voltage between the 2 terminals of battery.  This voltage should reach 13 volts DC as soon as you rev up engine (let's say at a high idling rpm).

Vincent Motorcycle Free Classifieds 1957 and 1959 Chloride Batteries LTD - Exide battery ads
I have always wondered why the empty battery case supplied by restoration suppliers did not seem to match the 1947-1955 era period Vincent photos. After searching thru 1950's era Exide motorcycle battery ads it looks like the case design was changed in 1958 or 1959.
So now we know this empty Exide case we purchase to look like a period battery is indeed an Exide motorcycle battery design, simply late 1950's. If anyone has further info please dont hesitate to contact me. I know the earlier Exide had a variety of Bakelite post knobs, some hex nut shaped, some large round knurled, some as shown.
It would be nice to have some period documentation on the colors used on the Exide battery case logo

The first (upper) diagram shows the insertion of a Podtronics rectifier/regulator and an 12 volt Alton generator.
It is a bit more detailed than the diagram below, showing all the connectors, wire colors and additional ground points.
This diagram shows a redundant - closed loop ground wiring system. This is intended to reduce dependency on the frame for ground purposes in the charging circuit.

The second (lower) diagram is as the bike was built using the 12 volt Alton generator and an Alton supplied rectifier/regulator.  It is a bare bones diagram.
I installed a key switch to correct the small electrical bleed off problem with leaving the battery connected for longer periods of time.
Within 2 years, the Alton supplied rectifier/regulator failed, and Paul Hamon recommended using a replacement.  I selected a Podtronics unit as installed in the upper diagram
  (Marc Michel  TT Restorations)

Discussion of modern Voltage Regulators:

I installed the Alton unit and I find there is a 23mA bleed to ground through the voltage regulator green ground lead.  The Vincent 12v battery was running down when simply sitting and the fault  traced to this.  What is my problem?  Craig Comontofski 11/7/2011

On the wiring diagram ("magneto" type) we suggest to add a switch to avoid a small leak current passing through the small black wire of rectifying  regulator when the bike is at rest. This is approximately 20 milliamps.  Not  very high but enough to drain a battery in a couple of days (depending on  the battery range).  So add this switch if you want to avoid this problem.  Another solution is to remove the fuse as soon as your bike is at rest for more than a couple of days. Or alternatively to use a home battery charger for long rests.    This inconvenience comes from the source of  rectifying-regulators. They actually come from small capacity Japanese  motorcycles on which the ignition key switches the small black wire of  rectifying-regulator (as indicated on the other diagram).  In this case no  leaking current because the battery is disconnected from the rectifying-regulator when the bike is at rest (ignition off).  If you start the bike without switching "on" and run the generator with  "open" circuit, it is not so good for both generator and  rectifying-regulator if you insist for all trip but it won't destroy them  for just a couple of minutes running this way.  By the way if you do so you surely can hear the generator "rumbling" and of  course the needle of ammeter won't move at all.   Paul Hamon   11/8/2011

Voltage regulators for DC generators have a requirement to isolate the battery from the generator's armature when the armature is not rotating. Failure to do so would put a load of around 1/2 Ohm (the resistance of the armature winding) on the battery. Mechanical regulators use a relay. Leakage of relays is so low measuring it would be counting single electrons. Solid state regulators typically use a diode. All diodes have a leakage current specification. The leakage can be measured without substantial heroics which is to say it is in the milliampere to microampere range. Solid state regulators for alternators use Zenor diodes to turn thyristors (SCRs) on. SCRs are just three of four (depending on how you like to count them) diodes in a fancy configuration. But we are back to diodes, things that leak. The diode can be specified to minimize leakage but at the price of compromising another specification. The design of a regulator (and just about anything else more complicated than a paper clip) is an exercise in compromise. There is no Utopia. Sorry, limitations of available technology. Doug Wood

Series "D" Vincent Distributor:
40455A dist service 40455/S clockwise turn 16-18 degrees DKX2A
Weights assy= 415729 ,
contact breaker complete = 400164
points = 400415 ,
cond = 400308 ,
cap = 400136 ,
springs = 421457/S
  Jim Wilson  11/10/2011

12 volt LED 7" headlight: 
Draws a lot of current, especially on high beam, 30W and 54W.   Paul Standeven & Bruce Metcalf  12/14/10  

NGK B6ES spark plug equivalents:  NGK 7432, Accel 143,  AC Delco 43XL, Autolite 2616, Beck Arnley 176-5002, Bosch  W8CC, Champion N5C, Champion 120, Denso W20ES-U, Denso 3051, GM  5613104, Mighty M4G3, Motorcraft AG3CX, Prestolite 14G3, Splitfire SF405F.    Bill Babcock  8/30/10

U.S. spec Miller headlight shell on that machine which originally took a GE 3044 sealed beam headlight.  Peter Guldan 8/17/10

For the best 6 volt  battery at the best price try the toy section at wal-mart.  The 6volt battery they sell to power the vehicles the kids ride in is actually a good battery and the most inexpensive I've encountered,  besides being the right size for the dummy battery box.  Bob Bonato  8/17/10

PODtronics regulator:
  - RED wire of the regulator to the ammeter
  - BLACK wire of the regulator to earth
  - YELLOW wire of the regulator to the D terminal of the generator
  - GREEN wire of the regulator to the F terminal of the generator

Your should also insert a fuse before the ammeter.  I use 15 Amp.  If your battery if heavily discharged when you first commission the system you may blow the fuse if you turn the headlight on.  Actually it is an inexpensive and meaningful test that I have run accidentally.  Assuming I built the generator (or at least it was wired as I would have), to motor the generator:
  - temporarily connect the F terminal to earth
  - temporarily connect the D terminal to +V
The armature should rotate smoothly clockwise as viewed from the drive end.    Doug Wood  5/14/10

So far there has been three electric starters for Vincents. Both Grosset and Conway starters operate through the gearbox mainshaft and the primary drive. Both these are more safely operated with the help of the valve lifter or a decompressor, particularly if there is a chance of a kick-back or if you have a very high compression ratio or radical cams. Bob Dunn's version (also seen on Dick Craven's Prince) drives the crankshaft directly and appears to be immune to such phenomena. But its not as pretty.    I always use the valve lifter (Conway starter) but there have been occasions when I forgot. That's ok with a warm engine but otherwise the load will hammer any battery (up to 16Ah) into low voltage at which point the starter solenoid tends to drop out.  Eddie  3/7/10
Altette Horn Manual:       10/3/09    8/21/10

To test your Miller D6 first determine which of the four wires are the field coil and which are the resistor.  To do so measure the resistance between all pairs.  If you measure two wires not connected, i.e. one from the resistor and one from the field coil you will measure a very high resistance. The resistance coil will measure two to three time higher than the field coil.  The resistance coil can be ignored for the moment. Pair a field coil wire with a brush.  Don't stress over which wire or which brush.  Pair the remaining field wire with the other brush.  Connect the two pair to a battery.  It does not take much thought to realize that the armature, the field coil and the battery are now all in parallel. The generator should now motor.  It should motor smoothly.  If it does not motor smoothly something is wrong and should be addressed.

If the armature rotates CW as viewed from the drive end then you guessed correctly.  If not swap the field wires and try again. Now take you volt meter and connect it in place of your battery.  Drive the armature CW and your generator should create a voltage.  If not something is wrong and needs to be addressed.
If the generator passed all tests is basically works and you can consider wiring it as a Lucas or as a Miller.     Doug Wood  5/29/09

Miller dynamos, as originally wired, work differently then Lucas.  Millers have three states of operation:
1.  Output voltage is too low
2.  Output voltage is about correct
3.  Output voltage is excessively high.

In the first state the armature voltage is impressed directly across the field coil.  Assuming that the cut-out relay is closed this would also put the battery across the field coil.  If the voltage is low enough then the battery will be disconnected (as in start up conditions).  This will maximize the current flowing through the field coil, implying a maximized magnetic field.

In the second state, where the system has equilibrated (sort of), the current through the field coil is decreased but not to zero.  There is a resistor that is inserted in the field coil circuit.  The resistor, which is the second winding on the field coil (wound non-inductively) is the mechanism for decreasing the field coil current.

The third state has no current flowing through the field coil.  Without this current there can be little or no output voltage.

While this system sounds good, in practice it barely works.  It is a fragile design that typically has been abandoned for the simplier Lucas type voltage control (states 1 and 3 only).  I am not aware of any solid state regulators that will support the Miller regulation design,  This is not to say that they could be designed but rather that there would be little demand for them.  Based on that assessment I would hazard a guess that your 30 year design would require rewiring the Miller.

FWIW I will not rebuild a dynamo in the Miller configuration as I do not trust the reliability of the regulation system.
Doug Wood  5/28/09

Even if properly polarized, if you're not providing 6V/12V power to field coils when testing ouput on the bench .... or a lathe, then output is very negligible,  like less than a volt at lower rpm.  To put it in perspective, most mechanical regulators excite (switching on power to the field coils to begin charging) at only .50 volts - and a POD at .75 volt -  generator output as the generator is only using residual magnetism within the field coils at that point to produce anything.   Peter  5/27/09
Alton 2 phase 12 volt battery:  Yuasa  BZ14. 14 amp hour 12 volt battery, as recommended by Francois Grosset for his electric starter. It fits the standard carrier without modification. 

Old Lucas Booklet:  All about Dynamos:      Bruce Metcalf

Gel Battery: This one costs a bit more but it fits very nicely and puts out 14 Amp hours which is unusually high for a small 6 V .  Size is 2 3/4  x 4 3/16 x 5 1/2. Called the dealers and the price was $29   2 years ago.  Mike Hebb  4/12/09

Gel Battery:    6volt, 14 amp.  Check the dimensions.  Mike Hebb  12/12/09

WESTCO 6 Volt Gel Battery

6.5'' and 7.0'' HELLA headlamp complete w/ a parking bulb that Fits our Miller headlamp shells.  All @ $19.00

Store Name: PUMA Store
Address:1670 Enterprise Pkwy.Unit E Twinsburg ,Ohio 44087 USA
Phone: (800) 354-
Fax: 330-425-2818

General sources of 6 and 12volt Halogen headlight bulbs:
Also, JC Whitney has them in 55/60W. Part number is ZX304576F.
Carl and John  12/1/08

Hella headlight unit:  Q.  Are these "right hand dip" US style, or do they, er, swing both ways the way Cibie units did?   A.  For UK applications use the repro unit designed for the Honda CB250N Superdream. It drops straight in and takes the H4 P43T standard bulbs.  Neil Diggins  12/1/08
6 Volt sealed battery:

Headlight:  I used a Honda V45, 1982-83 headlight #33120-MF5-751. It comes as a unit. You break the glass chisel out the caulking and re-install the unit into your Miller shell. It accepts a 65W quartz halogen bulb.  With the Miller lense in place you can't tell what kind of reflector is used.  Franc Trento at is reproducing precise replicas of the Miller lense.   Carl Hungness 9/4/07
Headlight: I am pretty sure that a HELA #70003 light unit will fit a 6.5 inch rim.   John Mead  9/4/07
Bosch   GL9
Points  = 1951-57 Reliant    Bosch   GL98 Condenser =1953 P24 Plymouth- Sunbeam-Vauxhall Velox
These are the correct points and condenser for the Vincent Distributor (DKX2A). They are readily available in any Auto shop  in Australia.   Greg  6/18/07
Dynamo Checking: Let us assume that you want negative earth as Vincents (certainly with a 3-1/2" dynamo) should have.  Also I will assume that the dynamo is off the bike.  If you position the dynamo so the commutator end is toward you and the armature at the 12:00 position the brush on the left side should be the ground brush and the brush on the right the positive.  Additionally there are two field coil wires coming from the bowels of the dynamo, one of which may or may not have an ientifying tag.  Small matter. Temporarily connect one field coil wire (doesn't matter which one) to the ground brush and the other to the positive brush.  Now connect the battery to the dynamo, actually now a motor, one battery terminal to each brush, negative to the earth brush.

If the armature rotates clockwise viewed from the drive end we have the field coil hooked up correctly.  Otherwise reverse the field coil wires and repeat.  It is necessary to get the dynamo to motor in the correct direction to ensure the field pole shoe is properly polarized.

Now comes the time to connect the regulator.  In general there are two types of which I know: high side switching and low side switching.  What does that mean?
The dynamo output voltage is limited by switching field coil on and off.  Output voltage too high?  Disconect the field coil.  Output voltage too low?   Reconnect the field coil.  Only one side of the coil is disconnected.

PODtronics and (I believe) Bell regulators switch the low (negative) side of the field coil.  This is true irrespective of positive or negative earth.  I cannot say with certainy anything about the switching of the JG or K-Tec units.

There are at least two 4BA screws coming through the brush plate.  One  of them may be common to the positive brush (it is when I rebuild a Miller).  It is worth checking with your Ohm meter.  The other is probably just a tie point for a field coil wire.  Check for (lack of) continuity to everything.    Doug Wood  6/1/07

Relays & Switches: Itís surprising how much you can get into the headlight shell. In mine, Iíve got a couple of automotive-type relays each wrapped in rolled-up strip of foam rubber so that they end up 1-5/8Ē dia. x 2-7/8Ē long. The fit in to either side of the ammeter.   One of mine is a latching relay (e.g. ), and the relays are rigged up so that only a single thin wire goes to a simple push-button switch on the handlebars. When the headlampís switched off, the push-button acts as a flasher (using both headlamp filaments), and when the headlampís switched on, the headlamp toggles between main and dip with each press of the pushbutton. My ammeter has a white plastic translucent case, and as a main beam tell-tale, Iíve got a couple of LEDs mounted on a tiny piece of Veroboard on the ammeter fixing studs so that the ammeter glows green when on dip, and blue when on main beam (and also of course so I can see the ammeter reading in the dark).    Iím running a 6V Altette horn on 12V, so Iím not worried about voltage drops in the horn wiring, and I donít keep my finger for ages on the horn button, so I use a similar thin wire between the headlamp shell and horn button.

Iíve made a replacement for the throttle twistgrip body with a homemade switch built into it for the horn. On the left-hand side, Iíve got a symmetrical lump of stainless which (i) acts as the clip for the valve lifter main bracket and (ii) houses the dip/flasher switch. The two thin wires run in a length of heatshrink from the headlamp shell to the underside of the handlebars between the handlebar mounting clips, where they go through a little hole and then run in opposite directions inside the handlebars and come out through little holes next to my lumps of stainless. All in all, it results in very uncluttered handlebars, with the clutch and valve-lifter levers and the horn and dip/flasher switches nicely placed.

The other nice feature is that the stop has broken in the Miller light switch, which fortuitously provides an extra position in which only the pilot bulb is on, so that can be used as a daytime running light without wasting precious Millertricity on the tail and speedo bulbs. I think Iíve got one of Goffyís ( 23 W halogen bulbs ( in there as the pilot bulb.   Ken    5/26/07

Wiring Harness: Boating suppliers like West Marine carry wire, sometimes referred to as "boat cable" or "boat wire". that is much superior to the bare copper sold in auto parts stores. It has finer, tinned  strands, so it is more flexible and corrosion resistant than the auto store stuff, and easier to
solder. Steve Lindbloom  5/25/07
Battery Ground: This all imprtant connection is relegated usually to the common thin wire held against the side of the oil tank,  usually a high resistance affair.   Use a heavier wire  with a suitable eyelet bolted to one of  the studs holding left side plate  FT 5 .  If an electric starter is fitted this grounding  becomes even more critical.   On the Vincati we use a heavy ground cable from the battery post sourced  from a big  Jap bike  - the size of your little finger.   All  ground wires possible connect to a heavy common cable and also bolt to this plate.    All lights are brillant and the Alton worked  powerfully from day one.   The battery stays up beautifully too.   We   run twin in line fuses - one for the general system, another for the starter 's  solenoid  circuit.    A key switch shuts off All power after it passes through the fuse, then supplies these two systems.  Thus there is no drain nor hot wires with the keyed switch { beyond the switch }  turned off.     Sid  5/25/07
Modern Lights:   A good headlight replacement is the HELLA unit. The glass cut is very good for driving, directing the light where it needs to go. The glass sticks out from the rim about a 1/16''. There are two sizes and not to worry about the ''T'' clip 6 1/2'' headlight shell/ rim, one of these two will fit.
  contact:     PUMA or Preformance Unlimited
30700 Bainbridge Rd
Unit L
Telephone 440 498 0638.  Fax. 440498 9647 (new address/phone 1/19/02)

The ''T'' Clip headlight unit takes #70003,    or hella #1A6 003 402 812 12V  unit 154  The cost is about $33.00 +/- bucks.
The 7'' split rim headlight takes # 70476  @ about $ 42.00+/- bucks
 Run a modern quartz-halogen headlight bulb an  H4 of amy voltage, any wattage and the nice thing about these are, they have a parking bulb (nobody I know leaves a light on when parking),  already  built in.  For those states or countries that require a 'lights on' driving situation, don't touch the actual glass of the bulb.  JS Wilson  9/26/01

Lucas Generator Parts Misc:
Generator - Lucas 20013
Armature - 200304, E3HM-LO 1946-47
Commutator end bracket - 200270 or 200269
Drive end bracket - 200353
Field coil - 200188
Through fixing bolts - 200227
Band cover - 200609
Brush set - 200290
Brush spring set - 200079
Brush gear (insulating plate) - 200431
Commutator end cover - 200354
Shaft nut - 170104
Bearing bush, Commutator end - 200231
Drive end bearing - 189307
Sundry parts kit - 249683

Jim Baltusnik 7/4/06

Lucas Distributor Parts Misc:
Series "D" Vincent - DKX2A
Bearing bush - 420406
Distributor base - 400001
Rotor arm - 400052 (not sure of this number)
Condenser - 400136
Shaft and action plate -
Coil - model LA-6 volt ignition coil, Part No. 45076
Contact breaker -
Distributor cam -
Clip cover retaining - 410591 or 420261

Lucas Magneto Parts Misc: (for "C" Shadow and Rapide): (for extensive Magneto information please see the Magneto Tech Section)
KVF GM1 42134
Contact Breaker Cover: 458647
Contact Set: 470877
Contact Breaker End Plate: 458633
Armature: 458679
Cam Ring: 458661
Contact Breaker Springs: 470688
Spring and Pin in CB COver: 458613
Slip Ring: 454497
Auto Advance: 47505

My '54 Rapide has what I think is the usual four-position Miller switch marked:
    "Ch" (which is still off),
    "H" (head, tail and speedo) and
    "L" (pilot, tail and speedo).
If you are unfortunate enough to break off the bakelite stop inside the switch, you'll find you aren't so unfortunate after all. You get a fifth position, and then a repeat of the same five positions with the other end of the knob pointing at the markings. The extra (unmarked) position gives you pilot only, without speedo and tail, which is great for daytime running especially with a bright little halogen bulb for the pilot.  If you want to go a stage further, you can swap the dipswitch and pilot light connections to the switch. The "H" and "L" markings on the switch are then the wrong way round, but the fifth position then gives you head, again without tail and speedo. Ken Targett  7/16/06
Battery: All other batteries I've run into sort of fit and put out  6 to 10 Amp-hours. This one fits very nicely and puts out 14 Amp hours.  Size is 2 3/4  x 4 3/16 x 5 1/2. Called the dealers and the price was $29.  See  if intersted.  Mike Hebb  6/18/06
Headlight wiring:  when fastening wires to the Lucas brass connectors in the headlight switch or horn..... always hold the connector with a small open end wrench against the tourque of your screwdriver.... this will prevent the connector from tearing loose by breaking the plastic or compressed insulation material used on the horn.(You have disconnected the battery- haven't you?)  Rip Tragle  4/26/06
Marchal headlight bulbs for Miller 6 1/2" Vincent Headlights:  I stock 6V 35/35W Quartz halogen Marchal headlight bulbs.  These are a direct replacement for the original and a lot brighter.  They are £12.00 ea. ($21.00).  I also stock 6V 10W & 20W quartz halogen pilot bulbs in both 9MM ad 15MM bases.  these are ideal for a daytime riding light.  £4.00 ea ($7.00) Post to US 2/3 days £2.00 ($3.50) Visit my website   Paul Goff  3/26/06

Headlights: A fine replacement for the stock Vincent reflector can be had by obtaining a 1982-83 V-45 Honda reflector. It fits into the Miller 7" assembly perfectly and of course accepts the quartz halogen bulb assemblies. Carl Hungness  3/23/06
Kubota alternator  (15531 64010) and regulator (19267 64602) can be adapted for Vincents.
McDouglator Technical Article by Carl Hungness

RB 107 Lucas Regulator info:

Vincent headlights were in three configurations to the States. Early had the 8".  Later came with the 6 1/2" which utilized a bulb.  Also common in the States (and France) was the sealed beam headlight.  (Lucas 400 series 7 inch)   These had a different rim that was split at the bottom. It also had a locating notch at the 11 o'clock position for the sealed beam unit. These are really two different components. The most distinctive thing about the Miller headlight utilized (by Vincent) was the triangulated boss on each side where the bolts screw in. I don't think that Vincent used the 7" version which has no boss but then I'm not sure.  I don't think that Phil Vincent would come running into the assembly line shouting " Shut down the production line, Miller can't supply the proper  61/2 units and we can't have concours judges arguing 50 years from now."  Velocettes also used them as well as the 7" units. To confuse things more, when Harpers took over both, if you ordered a headlight, they would send a 7" unit with a Vincent wiring harness. Not that any of this mattered, they were all connected to Miller generators.  Somer  1/1/05
A Vincent does not have a
7 inch headlamp Shell- that is Velocette. Vincent headlamp is 6.5 inch nominally.  (The lamp does not vary in size [but nothing surprises] however  7 " lenses Were sometimes fitted with a big rim for the USA market. With a tape measure, measure the arcate (accurate ?)  length of the bit that sticks through the rim ...6.5 inches or it's just under 6.5 inches at the widest point.. with a ruler. OK replicas of the 6.5 inch unit are now available from a Velocette guy (ironically) in UK who makes them in India. The glass is not right but OK.   Arthur  1/1/05
Podtronics manufacturers two entirely different types of  voltage regulators.

#1 For AC alternators.  Turns AC into regulated DC.  Creates heat in the process. This is a rectifier-regulator.

#2. For DC generators. This is a true regulator and controls output by modulating the field current.  They generate a small amount of heat as a by product.

The above mentioned #1 regulator is intended for AC alternators such as used on late BSA, Norton & Triumph.  Also used
on Alton, which is an AC alternator.  This regulator-rectifier turns the AC into regulated DC, and turns excess electrical energy into heat.  Do NOT cut off fins.  Do NOT mount in enclosed space.  Do NOT mount in Miller box.

#2  The second Podtronics regulator is a DC regulator intended to be used on DC generators (dynamos) such as those used on 50's (and earlier) BSA, Norton, Triumph, and Vincent using either Miller or Lucas generators. These are very efficient and yes, they CAN be mounted inside of the old mechanical Lucas and Miller regulators.  There is a small amount of heat generated as a by product, but is of no consequence.  (All components inside this regulator are certified up to 125 degrees C.)  We have done bench testing using a fibreglas replia Miller box with no problems after an hour of running time.
Bob Kizer  12/11/03

Great list of sources for Generator and Magneto repair:
jim 11/11/03

Ignition Advance: Blued pipes occur as a result of idling and running  with the ignnition firing point being held too long too near TDC.  The result is burning being sustained too far down the power stroke, actually a plume of flame extends out the exhaust port and down the pipe for about  8 inches - more or less.  In fact mixture correctness can be judged by the flame's color.   Extreme top end heat and oil temperature results as the cooling fins are unable to dissapate the added heat. Sid Biberman  7/8/03
Waking up a Generator: In order for the generator to start spontaneously there needs to be some residual magnetism in the field coil shoe or less likely the generator body itself.  The shoe is made of (I believe) soft iron and as such has fairly low magnetic retentivity.  So you have to "flash" your field on occassion. Flashing the field forces a curent to flow through the field winding creating the attendant magnetic.  The domains in the field shoe align  and remain so when the field is removed.  This is the afore mentioned residual magnetic field.

How to flash your field? Assuming you have a negative earth system and a Bell regulator, try temporarily connecting your armature output (possibly labeled "D" or if color coded a yellow wire) to the + terminal of your battery.  This will bypass the "cutout" diode in your regulator.  Then momentarily (< one second) connect your field output (labeled "F" or perhaps a green wire) to ground.  Your field is now flashed.  Disconnect all temperary connections and reconnect permanent connections.  Doug Wood  4/21/03

Headlight bulbs: The six volt is a "Stanley" brand, # A6867 . 6V30/24W. You should be able to order a box of 10 from a good Auto parts source. The side lamp is a 6V bayonet base flash light (four cell) bulb. If you think the bike will be used in the dark, I'd highly recommend that you contact Bill Easter for a Quartz lamp conversion.  John  6/24/02

Armature Failure: If you have positive charge when lights are not on, then it sounds as if your headlight is drawing an excessive amount of current.
1.  Try installing a standard 25/35 watt headlight bulb (25 watt low beam) and see if that makes a difference.
2.  Check to make sure that both high and low beam filaments are not on at the same time.  This will put a tremendous load on the dynamo.
3.  Make sure you have a seperate ground wire running from battery chassis earth to headlight earth.  Bob Kizer  4/21/02
Armature Failure: In all my years of refurbishing dynamos, the usual cause for shorted turns, open turns, or shorts to the core is because the owner expected too much of a device which was made cheap. Often the regulator was set too high so that the overall charging rate exceeded 10 amperes plus the two amperes required for the field winding, thus causing the windings to overheat or the solder to get thrown out of the commutator. Rewound armatures with modern insulation and being dynamically balanced can go a long way toward improving reliability.   Perrry Gerhart  4/21/02
Battery Technical Site:   ( updated 8/30/10 )
Amateur's Guide to Horn Restoration: I've stripped and repaired several horns and there's not much to them. They contains a coil, and set of points and a diaphragm. The points are in series with the coil and when they open, the coil's magnetic field collapses. They are so positioned that when current enters the horn  the coil pulls the diaphragm inwards and opens the points which collapses the field which releases the diaphragm  which closes the points and gives us magnetism again and again and again... .

My steps are:
1. Disassemble - You shouldn't have to open the big nut in the middle of the Diaphragm but open everything else.
2. Clean any spider nests and rust out of the inside.
3. Check the current path for opens or shorts.
4. Clean the points and all screwed connectors to bare metal.
5. Clean and oil all threads.
6. Check coil for continuity. If it is bad, give up and get it rewound or find another horn.   If you don't have a meter, briefly apply voltage through the coil and see if you get magnetism.
7. Make sure the adjusting screw on the back really does change the point gap when turned and the spring works.
8. Reassemble and test. Use adjuster on the back to adjust the horn tone and volume. If it makes just one pop of the diaphragm when you try it, the points are not opening when the diaphragm pulls in. If it makes no noise, then the points are open when current is initially applied and they should start out closed.
9. When you get some noise, turn the adjusting screw till the sound stops in both directions and pick the best tone in between.
Be especially careful where wires attach to the back. If they are open and can get wet, it can short from the connection to the horn body and cook all your wiring. On the Vincent the horn wire is always hot and it's activated  by providing a ground path with the switch. An inline fuse is advisable.
10. Polish, paint, rechrome or whatever you like to the outside and you're in business.
Mike Hebb   3/9/02

Vincent Twin Electric Starter:  (Note: a complete set of Vincent installation instructions is available here.)
Four different designs of slip clutch and electric motor were tested during the development of the Vincent electric starter. The Mark IV version has been selected after a test period of 1000 starts which consisted of 50 starts per day for three weeks.
An 1100 Watt starter motor,located under the gearbox,is mounted on a special ďG50Ē alloy pivot plate and is quite inconspicuous. The power is transmitted to the gearbox mainshaft via a reduction gear (400 RPM at crankshaft). A specially designed slip clutch is used to disconnect the starter motor when the engine is fired. The original kickstarter remains operational;
G46 rachet pinion needs an easy modification with a lathe. A 12 volt 12 amp/hour jelly battery fits into the original battery carrier.(Yuasa YTX 14BS), only a longer anchor stud and modified clamp strap are needed.  The extra weight to the machine is approximately three kilos.

No alteration to the crankcase is necessary. A slot must be machined into the kickstart cover. This modification is reversible. Should you wish to return to the original design, weld a piece of alloy to fill in the machined slot. The conversion is delivered as a kit including all the necessary parts exept the battery which is available from any modern bike shop.The kickstart cover and rachet pinion may be sent to the address below and will be returned Ďready to fití with all the parts.The assembly can be done by any good Vincent enthusiast mechanic in a standard workshop.

Price :    1400 Euros the complete kit with a second hand checked starter motor,
                             available for positive earthed machine only.
              1500 Euros the same complete kit with a brand new starter motor,
                            available for any positive or negative earthed machine.

               Prices do not include postage or shipping charges.

Contact: Francois Grosset, Le Pont Ricoul, 35720 St Pierre de Plesguen, France.
             FAX: 33-299-73-94 17                 E-mail:

KVF Vincent Magneto Trivia
KVF dated 3/46 P403K, C225
On one side of the mag body, up by the flange, is cast P403K.
180 degrees out, on the other side of the magneto is *stamped* LT7277
 Stamped coaxial with the armature, mid body, left side viewed from drive end.
    H84 stamped coaxial with armature, mid body, top.
    Both mags have the letter U stamped on the bottom, close to the
mounting flange.

KVF dated 1/51 P403K, H84
KVF dated 3/48 P403K
KVF dated 12/51 P403K cast in circular logo 1/2"dia.       jim

Modern Lights:   A good headlight replacement is the HELLA unit. The glass cut is very good for driving, directing the light where it needs to go. The glass sticks out from the rim about a 1/16''. There are two sizes and not to worry about the ''T'' clip 6 1/2'' headlight shell/ rim, one of these two will fit.
  contact:     PUMA or Preformance Unlimited
30700 Bainbridge Rd
Unit L

Telephone 440 498 0638.  Fax. 440498 9647 (new address/phone 1/19/02)

The ''T'' Clip headlight unit takes #70003,    or hella #1A6 003 402 812 12V  unit 154  The cost is about $33.00 +/- bucks.
The 7'' split rim headlight takes # 70476  @ about $ 42.00+/- bucks

 Run a modern quartz-halogen headlight bulb an  H4 of amy voltage, any wattage and the nice thing about these are, they have a parking bulb (nobody I know leaves a light on when parking),  already  built in.  For those states or countries that require a 'lights on' driving situation, don't touch the actual glass of the bulb.  JS Wilson  9/26/01

Testing your Armature: One side of the condensor should be unsoldered.  I would recommend the side opposite the HT turret on the slip ring.  Primary (low tension) resistance as measured from the amrature core to the wires that you just unsoldered shuld be approximately 0.5 Ohms.  Secondary (high tension) resistance measured from armature core to slip ring brass should be 5000 - 5500 Ohms.  Doug Wood  06/24/01

Polarity: With everything connected up just depress the cutout contact for a few seconds.  This will direct charge from the battery around the field windings and re-magnetise the field magnets with the correct polarity. 
Battery: Walridge Mtrs list a 6 volt black rubber original style ( p.94/2000 cat. p/n 14075 2 $105.82 cdn).  Also listed is black rubber shell with lid similar to original 6volt battery (p/n 99-920 $47.96 cdn).  They also state they can supply 6 or 12v battery to fit inside case, no price or p/n given. They can be reached at E-mail:  or Phone: 519 641 2770  or FAX:  519 473 3960      John Cousens  05/06/01

I thought that I would put the facts on the table as to the development of the Alton.

This started back in , I think 1989, when I was seen by Herve Hamon with a Kubota alternator in my hand at an Annual Rally ( Fort Purbrook, Portsmouth). Herve went home to France, and having, at that time some paternity leave  French, you know) for a year. A lot of spare time on his hands ( after putting Ettiene in the crib in the workshop, they train them the right way in France!)  Work was then done in producing some prototypes, using several different methods of drive ,and speeds. When it was found to be successful, but lacking in as much that it could only be used on twins, due to the large diameter of the rotor, it was decided to manufacture one of  three inches diameter, so that it could be used on all machines that used a Miller or Lucas dynamo.

The initial prototype parts were made by me, including the tooling for blanking out the segments for the stator( soft iron)  Much time was spent between here (Hayling Island ) and Auray on the southern coast of Brittany. Unfortunately One of the early prototypes was seen on a French bike by a British journalist, and publicity was given , long before any real development had been carried out. I was flooded out with enquiries from all over the World. This was something I did not need, having a business to run , sometimes 50 calls in a single day, and me not being able to give a sensible answer. Nowadays most of the parts are made in France, with only some gears made locally here in Portchester.I do not have any involvement in the project

This is where I will disagree with the statement made that the magnetic pulsation's of the Kubota, are the cause of taking out the rollers on the primary chain. If a Kubota is held in the hand and given a quick twist of the wrist it will spin easily, until it slows down enough for the magnets to take over again . So when the alternator is running this effect makes no impression . What does happen is that there is a far greater load, than what was developed by the original dynamo. Bikes that have a Fiat or Bosch automobile dynamo have also been known to shed their rollers.  It`s the increased load that is the problem. That and poorly maintained chains , running far too slack.  Getting the sprocket in the right place , central to the links , and with a good clearance above the rollers, helps.  A plastic sprocket is being experimented with to see if it is a going concern.
Trevor  04/30/01

The rearlight wiring runs up one leg and the stop light wiring up the other.  Also if you look under the rear hinge, you will find grooves milled out for the wire to pass under this component and then onto the rear/stop light assembly.  D.J.P. 04/27/01

Do-it-yourself magneto: The ordinary multimeter applies only a few volts across the terminals.

Use a megohmmeter with 500 volts applied.  1000 megohms is a reasonable value.  The capacitor needs to be disconnected from the coil.  Test hot at 180F.  Test the coil for leakage, same way.  Test the isolated coil for passive voltage with the 200 millivolt scale on an ordinary multimeter.  The higher the voltage(5 to 50 millivolts) the more water is is the coil.  Bake
it out for  day or two at 180F( post bake voltage should be less than 10 microvolts) and recoat with coil varnish.

Encourage Doug Wood and Bob Kizer to write a manual for these tests, defects, and cures.  Perry Gerhart  03/31/01

<<Did you use a megaohm meter on the mag to verify that the condenser is working as it should?  This is the only way
to accurately check a mag condenser.>>

Yes, a megaohn meter will act as a capacitor tester as it will judge the ability to take on and hold a charge. (as does a capacitor tester) I"ve tested hundreds of Lucas capacitors and haven't found a "good" one yet.  They are all leaky to one degree or another.  Even if you find an NOS one still in the box, it will test leaky.  Lucas was ahead of their time in manufacturing biodegradable parts. (the capacitors used paper dialectric)   Bob Kizer  03/31/01

Along with people, magnetos and paper dielectric capacitors suffer from old age.  A 50 year old magneto has outlived it's usefulness.  To use a "band aid" approach is to only prolong the inevitable.  Overhaul it correctly, rewind the armature, use a good quality capacitor suitable for pulse application, and you probably won't have to do it again for another 50 years.
Bob Kizer  03/31/01

There have been a multitude of discussions, in print, about how to time your Vincent over the years and I have done my level best to research many of  them.

    The "poke your spoke" method of inserting something into the cylinder surely leaves much to be desired as far as accuracy goes. Moving the engine 5-l0 degrees is actually VERY little.

    Once again we refer to "40 Years On" where methods ranging from dial indicators to putting a bit of soap over the plug hole (and watching the bubble rise or fall) to give us Top Dead Center.

    No matter how you find TDC, it is a simple enough circumstance to install a degree wheel and check yourself. Then simply make up a spark plug stop (again see the method in 40 years On..whereby you bust up an old plug, thread a bolt into it, and set it precisely at TDC)

    I have utilized my spark plug stop guage a couple of dozen times to re-time my bike and am "chuffed like a parrot" to say more often than not she has started first kick after installing the mag.

    Once again, the installation of the mag, figuring out precisely where the points open, is covered in the "40 Years On" but to summarize, you take out the center bolt, hook up a small dash style light, watch it go on and off..and you 'll know precisely when the points break.The do break electronically a bit faster than visually...I know many have used cigarette paper and a "feel" method..which works well too.

    Measuring this spark plug angle is, yes, like measuring with a mike and cutting with an axe.I love that analogy..and had forgotten it.

`    Remember to block open  the ATD when setting the mag...

    I know from experience this procedure can be done on the road..and I feel confident the measuring down the hole method has started many a Vin over the years as well. My point is, make the spark plug stop, carry it with you and you'll never have to worry about where 38 or 39 degrees is again.       Carl Hungness  03/30/01

Here is a technical tip for all you Vin/Ariel members that have ammeters with the red jewel in it.  I modified Rob Arnott's ammeter by drilling a .099" hole in the back and gluing a super bright red LED into the hole with superglue.  The LED was connected in series with a resistor and the resulting illumination was very impressive with only 20 milliamperes
going through the LED when the ignition was switched on.  Polarity of the LED needs to be observed.  The Vincent had negative ground so I connected one end of the resistor to the anode, positive, longer lead of the LED, and the other end to the connection on the ammeter lamp socket with the white wire on it that goes to the ignition switch.  The shorter lead on
the LED was connected to the ammeter lamp socket with the yellow wire on it that goes to the dynamo armature.  This can be used for either 6 or 12 volt systems.  I used a 510 ohm, Ĺ watt resistor for Rob's 12 volt system.  A 240 ohm, ľ watt or larger resistor can be used on a 6 volt system.  Bill Easter  03/15/01
I had run a Mistral/Lucas Rita setup for a few years, (once I'd sorted out a reliable power supply) and it ran very well but,
1) It sucks a lot of power, like almost 4 amps on 12 volts. 2) I wanted to hide the coils under the Mag cowl and used small twincoils which would go about 3000 miles and just die. Burn them out, even expensive Dyna coils, although they did not measure the 3 ohms that they were stamped with. I didn't want the 2 big old Lucas coi;ls hanging out in the air so paid the price in coils.

I then switched to HD stuff fitted to the Mistral housing which I still run. Dan Smith started this, now many local bikes run it, and John McDougall has been making housings to suit. The benefits are many. Two stage advance curves operated by a vacuum switch. Low power draw. Parts available very readily. You can tuck it all under the mag cowl. There are for those who like to fiddle with that sort of stuff, programmable boxes that you can program more stuff than you'll ever need. Do you need to have&nbsp; nitrous arming and firing points?&nbsp; How about if you have and electric start you can program the engine to turn over a designated number of turns before it fires to avoid backfiring on start up.  Robert Watson  03/09/01

Engineer Kirby Rowbotham builds the Boyer Bransden "Micro-Digital" system into his own replica magneto housing, for mounting in the standard Vin magneto position, all for £320 (GBP320).  These run with the miniature "digital" coils supplied, to allow two-plugs-per head firing.  I think he advertises in CB, CBG etc. magazines.  His system is claimed to have independent (i.e. per-cylinder) EEPROM-based adjustability of timing curve.   Phil Blakeney  03/09/01
Does anyone know if you can run a dyno without a battery.  I think you need the battery to excite the field coils to get the armature to produce current or will this happen when the dyno begins to spin? John Mead

Hello John,   It depends upon what regulator you are using.  If you are using the original Lucas mechanical, there is no problem.
The voltage to excite the field actually comes from the generator armature and is switched on and off by the regulator. (this is how they regulate maximum voltage)   If you are using K-tec, then the answer is no.  Because the K-tec uses a Darlington transistor for field switching, which requires 1.4 volts to initialize, they use battery voltage to excite the field.   On the other hand, if you are using the PODtronics DC regulator, there is no problem as it will operate very nicely without a battery in circuit.  (and it fits inside the mechanical regulator box)  Bob Kizer  02/27/01

I have been using a 12V Alton alternator on my 'C' Shadow for a couple of years with absolutely no trouble at all.  It just always works and I would recommend one.  I find the "break-even" point to run my quartz headlight, instrument lights, and high wattage running light to be about 50 mph in top gear--that's fairly low rpm and certainly the wrong gear for that speed.  Its output is claimed to peak at 150 watts sustantially more than any 6V DC generator.

I tested prototypes for ALTON.  My findings were that electrically it was just fine right from the start and once they got into production any minor mechanical problems had all disappeared.  It's a nicely built piece of equipment and is a direct replacement for the original Miller unit except it is 12V.

BTW...I run magneto ignition--no particular reason except it has never failed me.  It does have an advantage if I leave something on and run the battery dead.  Jay Schaffer  02/13/01

A Dynamo is a machine that when driven by a prime mover, such as a water turbine or a Vincent, is called a
Generator. It changes mechanical energy to electrical energy. If a Dynamo is supplied electricity and it's output used
to supply power to mechanical devices it is called a motor. Generators are rated as to the Watts they can supply at a rated Voltage and Speed without Overheating. Motors are rated to the Horsepower they can deliver at a given Speed and Voltage without Overheating. Now Forget motors! This is about Generators!!

There are several ways to control the Wattage: (One) Speed Control, that's the thing your right hand does. (Two) voltage control. That's the thing the regulator does to the field windings of the Generator. There are two ways that you as a Vincent rider will deal with hooking up the field to the voltage controller. (One) in Series with the Armature; (Two) in parallel, or
Shunting, The Armature. You can hookup any Miller, Lucas, Bosch or Chinamo to do either. JG units are hooked series, or externally grounded, K-Tec, Lucas regulators are hooked Parallel or, internally grounded. By looking at the drawings in KTB, Richardson, diagrams that were supplied with your regulator or, by looking in an old Auto repair manual you'll be able to see these differences. Since all these Generators were made to run in motorcycles you can see the speed part of their rating can be anywhere from less than two thousand to over seven thousand RPM! If they are not overheating they are safe, so go ahead and spin the generator a little faster, it won't bother it a bit. One Hundred-Twenty watts at twelve volts is still in the working range
of Your Sixty watt, Six volt Generator.  John 12/20/00 

Looking at the diagram by JG, it appears that the gen is wired in shunt. I  believe that the JG unit varies the current through the field to regulate the output.  It is a parallel generator.    John  12/20/00

Dynamo:  I fitted a good condition E3L generator, only modified in the wiring as explained by JG, and a 12 volt JG regulator to my "D" Comet some years ago. The instructions with the regulator said that it would produce 12 volts with approximately double the output.  This is what it has done without any troubles, until I removed it about two months ago.

However, a later modification on this side of the pond is to fit the distributor from a car and have 12 volts with an out put of 15amps or more. One of the favourites is the generator from a Citroen  2CV, due to it's small size.  As I have plans to update my lighting and possibly fit an electric starter,  I have fitted a car generator to the Comet.  Of course there is much more room to fit it on the Comet, so I have fitted a slightly larger generator that has the rectifier pack and the regulator mounted under
the end cap.  This is driven from a small dummy dynamo incorporating a pulley at the non-drive end which in turn drives the alternator with a poli-V  belt. The finished results have been very impressive, with the alternator balancing the load of every item on the bike at a fast tick-over.  Derek Peters  12/20/00

When Joseph Lucas designed the dc dynamo, he did so with neither an excess of steel nor copper.  Of course, it depends upon what size wire is used in the 12v rewinding.  When going to 12 volts, less current will be required to do the same amount of work.  In order to get higher voltage (at  lower rpm) the wire must be smaller so that more wire can be wound on the armature.  And of course, smaller wire has more resistance, thus increasing the I^2*R (current squared times resistance).  So yes, all things being equal, you still have a 60 watt instrument.   However, by using a 6-to-12 volt conversion regulator, you can use that 60 watt headlight whilst utilizing that 6 volt armature.  The only "problem" is that you must spin it faster to get that full 12v output.

If you use a JG converter or similar you can use a 60/55 watt headlight bulb bulb. The converter will (or should) protect your delicate little field coil from harm by limiting its current.  At 12 volts, the field coil might draw as much as 6 amps.  Bob Kizer  12/14/00

Both a generator and an alternator do the same thing: convert mechanical energy (rotation) and magnetic energy (either a permanent magnet or a field winding) to electrical energy.  As Mr. Kizer so correctly stated: "There's no such thing as a free lunch."  If you want to get 60 Watts out of a generator you need to put 60 Watts into energy for all the losses.

If you are simply trying to run a 6 Volt generator at 12 Volts exercise caution: the field coil will have the full 12 Volts impressed across it. Since resistive power increases with the *square* of voltage (all else being equal) your poor filed coil will be asked to dissipate *four times* the energy it was designed for.  So generally the voltage across the field coil is limited to 6 Volts.  The easiest way to do so is with a series resistor.  But this may not be the most efficient.

The situation with the armature may not be so bad.  Again, assuming the desire is to run a 6 Volt generator at 12 Volts the load (lighting, field coil, accessories, etc) may be specified such that the current requirements may actually decrease (a primary advantage of higher Voltage systems).  In this case a 6 Volt armature may work... but at the price of requiring higher RPM.

My take on this situation is:
  1. A 45 Watt bulb puts out just about 45 Watts wether it is 6 Volt or 12.
  2. All things being equal 12 Volt systems require less current, therefore are more forgiving of sub-optimal electrical connections.
  3. There is an upper limit on what you can get out of a 35 Watt generator.
  4. There is no upper limit on what you can put into a 35 Watt generator, short term.
  5. It is my opinion that if you want a 12 Volt system you should convert to 12 volt components (field coil, armature).
Doug Wood  12/14/00

The generator/dynamo has two essential parts, the armature and the field coil. These can be configured in one of two different ways. 1) Armature and field coil in parallel with each other, and having a common ground (earth). This is the arrangement as shipped from the Lucas factory and utilizing the old fashioned Lucas mechanical regulator.
2)  Armature and field coil in series with one brush connection earthed, and the other brush sharing the "D" terminal with one of the field coil wires.  This arrangement is required for some solid state regulators such as the JG.  Although there are some solid
state regulators that require condition #1.

 You can flash the field for one of two reasons, or both. 1)  To reverse the polarity or 2)  To restore residual magnetism.  In this situation, we are doing it to increase the residual. Remember, the mechanical regulators can initialize with as little as 0.1
volt.  But due to the characteristic of silicon solid state devices, they must have in excess of  0.7 volts.  This can be  accomplished by either flashing the field, or spinning the armature faster and faster.  The residual magnetism decreases with time.  If the bike hasn't been ridden in several months, it's possible this will restore the lighting.

The Miller (and Lucas) should have two outlet termainals.  One should be marked "F", and the other marked "D".  The green wire from JG should go to the F (field).  The "D" terminal will most likely have blue or yellow.    I'm betting that flashing the field will restore operation, but if it doesn't, you might want to consider the PODtronics.  They are designed to be more efficient and
therefore consume less power,  thus generating less heat. And they're small enough to fit nicely inside the Miller and Lucas boxes.  And yes, the "hot" terminal is the one that isn't earthed.   Bob Kizer 12/14/00

Maybe all open "D's" were fitted with the Lucas model 564 tail light, but the enclosed models were fitted with model 529.  You need to ensure also that you get the right model 529, which is 53429A,  as they were also made without a connection for the Stop lamp.  Derek Peters  12/14/00
Regulators:  At one time JG was availabe epoxy potted inside of the owners Miller box lid.  It's my understanding that this feature is no longer available and can only guess it was because of insufficient heat sinking. (These generate about ten watts of heat at full output.)    Keep in mind that each time the bike is started, the generator creates output voltage using the residual magnetism from the last time it ran. Also, keep in mind the poles of the generator are soft iron and will not stay magnetized indefinetely.  The "drawback" of solid state regulators is that they require approx. 0.7 volts to initialize.  If most of the field
magnetism is lost, the regulator will not initialize.  But the fix is simple. (please note this applies only to generators wired according to JG  instructions)
1.  Disconect the regulator from the generator  (US generator = UK dynamo)
2.  Run short jumper wire from "F" to ground.
3.  Attach wire to hot terminal of battery.
4.  Briefly touch other end of this wire to "D" terminal on generator.
5.  You have now "flashed" the field.
6.  Disconnect the jumper wires and reconnect the regulator.
Bob Kizer  12/06/00
While we do have some very knowledgeable and able
craftsmen rebuilding both magnetos and dynamos who advertise in the VOC MPH journal, I wish to recommend a couple here stateside whose names and addresses seem to be fairly secret.
I have had excellent experience with a magneto rebuilt by Bill Jean 757 488-7l9l of Virginia (Sid Biberman's partner in the restoration field) and Rip Tragle revamped my Miller generator to l2 volts and after 20,000 miles seems to be working great...Tragle is of course a journeyman engine rebuilder as well..his phone is 9l4  676-3304.

Nevertheless,  after some correspondence with Mark Goodson I am pretty well convinced that the Chinamo he discovered is well worth looking generates a very healthy output, and is reasonably priced. Available from the VOC Spares company. The main problem with the generating system, my research has shown, is not the generator itself, but the regulator. And nowadays we have our choices of several modern ones that seem to handle the load with consistency

Personally, I love the idea of being able to start  the bike and drive it home, without a battery. Then again, after doing considerable damage to my knee last summer I am looking forward to the day I can afford an electric starter..but I'll still keep the magneto.   Carl Hungness  9/'29/00

How to fit an electronic ignition unit to a Comet.  I can only refer to suppliers etc. in the U.K.  Here most of the conversions seem to use Boyer Bransden units.  Kirby Rowbottom using a  Boyer Bransden unit can convert a standard magneto to contain the sensor unit, which consists of a magnetic rotor and a stator plate and then the only other component is a transistorised control box about the size of a twenty pack of cigarettes.  The only item not included is a standard coil.  Most of them are powered by 12 volts and I would recommend a conversion.  I used a standard Lucas E3L dynamo and a "JG" voltage conversion unit - this converts the standard dynamo to 12 volts while doubling the output to 120 watts.  If you have machining facilities I consider the way I did it to be the best solution.  I machined an alloy casing rather like a distributor and mounted it in the same way as the "D" distributor so that it can be turned to obtain that final timing adjustment.  This unit had two small bearings, a 1/2 " shaft and a cavity to contain the rotor and stator.  It is driven by a standard tufnel gear.  I dealt directly with Boyer Bransden, who I found to be most helpful.  Initially they recommended a unit made for the Triumph  &BSA Singles.  However, when I mounted it on the bike there was insufficient advance to allow correct timing for both running and starting.  I phoned their technical department and they asked me to return the control box.   Within a few days back came a new box bearing the inscription -"HIGH POWER IGNITION UNIT - SPECIAL: VINCENT COMET - WIDE ADVANCE".  Needless to say it has functioned perfectly ever since.
This advice applies equally to Twins.    Derek Peters     9/29/00

Altette Horn Repair

Issac Lynn "Taff the Horn"
20 the Glebe
Bishopston, Swansea,
West Glamorgan SA3 3JP
South Wales, UK

Lynn (known as Taff) Isaacs is a ruddy miracle man on all types of  horn. Has 9000 horns and specs on almost every one ever made. Got me one for my 37 Rudge Ulster, rebuilt my A and the C (12V conversion). Hardly ever uses pattern stuff (re wiring is new!!) and charges are embarrassingly modest.  (Authur)  7/18/00

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