The 'big' Lucas motor cycle parts list 1936 - 1957
Here's a good example of a very popular magneto; the Lucas RF4. This is a 4 cylinder magneto, most commonly found on old Fordson tractors. It works on the 'stationary armature' principle where the coil. Are you interested in this item? Lucas gj4 magneto with auto advance working condition - sparks well. I have cleaned the points and now it sparks to the body when twisting the shaft by hand. Details: catawiki, x-men, magneto, softcover, edition, click, orange, button, website, goal. Lucas Sr4 Magneto Manual. Lc dynamo magneto, magneto powertest video thanks. Lucas rs1 & sr1 magneto condenser replacement. Lucas workshop instructions, indonesia gold star, sr series magneto dynamo, magneto tips forward. Mo1l magneto powertest video thanks. Sr6le magnetos operating.
(Some of these are large files)
...Contact breaker units, distributors and suppressors (pages G2 to G7)
...HT coils (page G8)
... Magnetos and ATDs (pages G9 to G23)
... Magdynos (pages G24 to G40)
-2927x2341.JPG "Magneto")
...Flywheel magnetos and generators, and dyno-distributors (page G41)
...Gears for distributors and magdynos, brushes and springs (page G42)
...Bearings and bushings (page G43)
...Spanners and screwdrivers (page G44)
...Ignition supersession chart (page G45)
...Fog and driving lamps (pages H2 to H3)
...Headlamps (pages H4 to H39)
...Side and pilot lamps (pages H40 to H42)
...Tail, stop and number plate lamps (pages H43 to H48)
...Tank panel lamps, warning lights and reflex reflectors (pages H49 to H50)
...Lens chart for side, pilot, stop and number plate lamps (page H51)
...Lighting supersession chart (page H52)
...Bulbs (page H53)
For all orders and enquiries please use the contact details on the homepage. I do my best to keep my prices up to date but occasionally there will be increases due to suppliers' price changes. The price you see is the price you pay - no need to add VAT.
Standard charge to strip and rebuild on all jobs listed below £20.00
BSA A10 and Triumph pre-unit type ATD fitted with new fibre wheel and new springs £30.00
Shaft built up and ground back to remove excess play £30.00
Fibre gear replacement on manual drive unit £20.00
Rebuilt units supplied when available, BSA £120.00, Triumph £149.00. Part ex. (up to £40) value given on any units sent in.
Alternatively, do it yourself using the kit I supply.
Lucas Gj4 Magneto Parts
ATD and fixed gear kits (gears, rivets, springs and instructions available- See Retail sales from the menu on the left, magneto and ATD spares)
The instructions for fitting are here....... ATD repair
Lucas Rf4 Magneto Parts
PLEASE SCROLL DOWN AND READ THE WHOLE PAGE!
A bit of ATD theory!
ATD's can be a bit baffling! Occasionally customers phone me, whilst fitting their magneto, to ask if their ATD is faulty. The conversation goes like this... 'I'm fitting the magneto and just about to fit the ATD. When I hold the ATD in my hand it flicks back OK but as soon as I start to tighten it onto the magneto shaft it doesn't seem to flick back properly. I can move it backwards and forwards by hand but it seems to have gone stiff and won't flick back on its own. I've taken it off again but I can't find anything wrong with it. What's going on?!'
Think of the ATD as a component that works in three stages.... 1) the fixed gear picks up drive from the engine then..... 2) the drive is passed on to a flexible connection made of springs and bob weights, then... 3) the drive is collected from the flexible mechanism by a nut fixed onto the magneto armature shaft. Remember that the gear is fixed because it is meshed to the camshaft gear, so the springs are trying to pull the magneto armature back to the 'at rest' position whilst one end of each spring is attached to the gear and the other end of each spring is attached to the armature shaft. Now here's the critical bit.... (and the reason why the ATD doesn't flick back when stationary) ... the magneto armature is not free-floating because there is friction and magnetism in the magneto which prevents the armature responding fully to the pull of the springs. The friction/resistance is caused by the pickup brushes, earth brush, heel of the points, drag in the bearings and the attraction of the magnets. As the engine is turned over very slowly the friction is reduced because the parts are moving - sliding over each other, and the springs are able to pull the mechanism to its 'at rest' position. You can test this by turning the bike over slowly on the kick start and watching the ATD return to its fully retarded position - Hey Presto!
ATD units are not very sophisticated but they do need to work properly. The springs should be strong enough to return the unit to 'fully retarded' as the engine comes to rest - this will enable you to start the bike again without getting launched over the handlebars. If the springs are too strong they will prevent the magneto advancing soon enough which may cause overheating and sluggish running. Springs which are too slack will advance the spark too soon causing advancement at kick start speed (kick-back) and spitting in the carb when blipping the throttle.