detailed instructions in our 'condensectomy' Electrical - Armature windings, Condenser, Slip ring, Points and Bushes. BTH mags utilized condensers made from mica. [5] Therefore, some magnetos have an impulse coupling, a springlike mechanical linkage between the engine and magneto drive shaft which "winds up" and "lets go" at the proper moment for spinning the magneto shaft. A short circuit absorbs all the power, hence no output or spark. With a twin, repeat with the other pick-up. Copyright 2000-2020 by, ---------- Post added at 08:44:59 AM ---------- Previous post was at 08:39:49 AM ----------. A small number of electrons is ever present and over years or decades this flow carves out an ever widening pathway through the insulation. Values vary considerably depending on the make and model of magneto and who wound it. From the basic to the complex - some I wonder if hand-cranking might get it going. Nederlandse However, if the reading is more than 7000 ohms, there is probably either a break in the HT winding, or a bad connection between the live end of the HT winding and the slip-ring. Check the cam surface. Rotate the armature and check that the contact-breaker assembly does not foul its housing. Having removed the contact-breaker assembly from the magneto, disassemble it, noting where each part was. At atmospheric pressure, the voltage required to strike a spark across the 0.020 (0.5 mm) gap of a sparking plug is far less than the voltage required at the elevated pressure that the plug experiences in the engines cylinder. (Chinese) Capacitors are replaced with ones that have a longer life expectancy and greater reliability. tour of some of our specialised workshop VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. With a multimeter, check the resistance between the brass of the slip ring and the end of the armature shaft (armature earth). detailed guide to maintaining and With the contact-breaker assembly still removed from the magneto, and with a multimeter set to measure resistance, check that with the points closed there is a short circuit between them (as close to 0 as your multimeter goes). Lucas Ga4 Magneto Austin 7, Morris, Riley And Many Others Service Exchan. Trademark Office. In a modern installation, the magneto only has a single low tension winding which is connected to an external ignition coil which not only has a low tension winding, but also a secondary winding of many thousands of turns to deliver the high voltage required for the spark plug(s). Put a smear of grease on the tappet shaft. So, re-check everything in the contact-breaker assembly first before deciding on a more complete overhaul. old-style capacitor (the 'condensectomy') and This can mask a fault on these cars as the vehicle will continue to run until the other fails. I do not know it all but I will try to help. Capacitors, which are short-term storage devices, often fail in older magnetos due to dielectric degradation (short circuit) or conductor breakage (open circuit). books, learndpapers and patents on 2,330 views Oct 18, 2020 16 Dislike Share Air Fuel Mixologist 1.31K subscribers I purchased this Lister D petrol (gasoline). Main-body Earth Brushes and Bearing Insulators: Some magnetos have an earth brush between the contact-breaker back-plate and the contact breaker housing. This is really common on original units as the Lucas condensers were made from wax paper and foil. They were used in the village forge in Cullworth (northaptonshire). The Fora platform includes forum software by XenForo. For example, in the Lucas K1F and K2F, the earth brush is located on top inboard of the main mounting flange. and just how were you able to find one of those bastards that still worked?!?!?! I can guarantee every British motorcycle powered by a magneto i either not delivering maximum spark and/or is on the verge of failing if the original Lucas capacitor has not been replaced. Check for any dirty marks on the paper. If you can't get even 1/4", I would be worried it would not work under the stress of being in the combustion chamber. Translations provided by the Google BTW, Michael, that's a darn clever trick/solution! This allows the spring to unwind giving the rotating magnet a rapid rotation and letting the magneto spin at such a speed to produce a spark. The condensers we get now are made in area's that there are no or very poor quality control checks. You are using an out of date browser. Over time the HT leads can degrade and reduce the potential difference at the spark plug. If possible, get somebody to help. This is really common on original units as the Lucas condensers were made from wax paper and foil. that more owners can not only maintain their magnetos, -- misfiring, particularly at higher revs and fully open throttle, or when opening the throttle. The other plug cap should give a reading that is infinite (OL) or extremely high. asked questions, some of which isn't to be Copyright 2023, Antique Automobile Club of America. We also have kits for more unusual magnetos, such as the BTH, ML, Magnetos France, Morel, Lucas wader, Lucas KVF, etc., and for cars. Therefore, taking the sparking plug(s) out of the engine, laying them on the cylinder head and checking whether the magneto will produce a spark at kickstart speeds is not a sufficient test. Make a note of the reading; youll need to refer to it later. - there's a lot of stuff in our frequently If youre giving your magneto a thorough check over, we suggest you tackle jobs in the order shown. The place to buy our EasyCap condensers The Magneto Guys - Vintage, Veteran, Classic Magneto Repairs Lucas Magnetos We have overhauled and repaired these Lucas magnetos and then returned them to their owners. From time to time we have complete [3] The capacitor's function is similar to that of a snubber as found in a flyback converter. i totally agree. Tri-Spark Ignitions; Pazon Ignitions; Lucas Rita; AGM Batteries For Classics; Lucas Alternators; Rectifiers & Voltage Control; Dynamo Parts; Magneto Parts; Lucas SR Magneto Spares; HT Coils For Classic Bikes; British Bike Points & Condensers; . In the case of a main-body earth brush, try moistening a cotton bud with petrol, and poke it through the hole for the earth brush to clean the track while rotating the armature, but IMPORTANTLY before doing that temporarily remove or disable the contact breaker to reduce the risk of electric shock and fire. English found in all rotating-coil magnetos. Pick-up, HT Lead and Plug-cap 1 Housings can sometimes get misshapen, in which case try to rectify that. Checked it over and found no spark. Some have both types of earth brush. If everything were perfect and clean, the resistance should be infinite (OL). If there is a difference, adjust the points so that it is the smaller gap that is 0.012 (0.3 mm). Replace the main-body earth brush, if applicable. Magneto coils are usually a long time dying. Gift Article. Sign up for a new account in our community. Trouble starting my 1924 Citroen engine. I was bench testing by tuning the mag slowly by hand, without the impulse coupling attached, so 1/4" is a good distance. unfortunately the repair did not work as the Coil did not work so it had to be sent to rewinding. A Not sure what came off, but 1930s/40s I would have thought.prefer collection, but would post. Lucasworkshopinstructions-magnetosLucasworkshopinstructions-otherstuffLucaspartslistsLucasATDspecificationsBTHinstructions&partslistsM-LBookletsMagntoFrancedocumentationRobertBoschDocumentationAmericanBoschworkshopinstructionsPatentsBooksandlearndpapers, Redesigned contact breaker for ring cam models, SR1, SR2 & SR4 magnetos (workshop Our preferred gap for spark testing in fresh air is 6 mm. <]>> at some of the equipment we use in our workshop for magneto servicing Now that the slip ring has dried off, replace the pick-up(s). For example: Check as best you can that the brush is actually making contact with the track on which it runs. Click on a button to see magnetos from other manufacturers Bosch BTH Others Click on any picture to get a larger view Downloadable drawings, all for free, for Lucas Magneto 1930 - 1940. In the inductor magneto, the magnet is rotated and the coil remains stationary. 0000005468 00000 n These faults do not necessarily occur instantaneously, they may develop over time leading to a gradual deterioration of the spark output. Dansk anglais, votre convenance. Excellent "how-to". Lister D Magneto Lucas RS1 full rebuild but still no spark Coil Fail. Norsk Remove the cam, carefully noting which way round it goes and which notches in it engage where. Franaise Deutsch You should not let a Wico X go out the door if it will not jump more than 1/4" because something is wrong. Posts: 34. Feel free to buy the forum staff a coffee or pint or just make a contribution of your choice. Turn the armature in its proper direction of rotation until the contact-breaker points are just starting to open. 0000003086 00000 n I'm working on a Lucas Mag right now for the first time and this is extremely helpful. The plugs are non resistor, gaped at -025", and are new. We can adapt for most applications. LUCAS K1F MAGNETO RUNNING AT 1200 RPM AT THE ARMATURE. grade to avoid carbon deposits on the slip BTH mags utilized condensers made from mica. The permanent magnet can be static, as in the classical horse-shoe form, with the transformer windings rotating between the poles, or sometimes the magnet is mounted on the armature and rotates within the core of a static winding. Svensk [5] The hub of the magneto rotates while the drive shaft is held stationary, and the spring tension builds up. The resistance between the two sides of the circuit board (with your fingers well clear) should climb to in excess of 2 G (2000 M). any service or repair work until further notice. Please note: THEY ARE NOT FOR SALE! In early magnetos the magnets were formed from a cobalt material and had to be remagnetised if the armature was ever removed. Another cause of atom disorientation is mechanical shock, hammer blows or dropping the unit onto a hard surface, etc. If it is significantly higher, there is a bad connection or break in the low-tension circuit, in which case the magneto will need a more complete overhaul. It's a 6v system, so the starter turns rather slowly (maybe 80rpm), but I think it should be fast enoughto start. 0000001015 00000 n Put it on bike, timed, no spark. (Chinese) rectifiers (and wiring diagrams) of use to all Thanks mmcdonald, all good info. With an open circuit the device has no CAPACITY to absorb the reaction voltage (back EMF) from the coil, therefore this energy is dissipated across the timing contact which quickly burns away. If it is significantly lower, then there is probably a short-circuit in the contact-breaker assembly or in the armature. A short circuit absorbs all the power, hence no output or spark. Norsk Your mag likely has a bad condensor. Brightspark Magnetos Ltd disclaims responsibility for any errors You are probably loosing amperage through the jumper cables. slip rings and pick-ups for Lucas and BTH With twin- or multi-cylinder magnetos, and some single-cylinder magnetos, the brass is a segment, rather than a complete ring, and you may need to rotate the armature in order to be able to see it. Without suppressor: suppressor: Percentage difference with suppressor: Peak HT voltage to initiate spark: 9600 V: 10600 V at magneto: 10.4 %: 9300 V at spark gap-3.1 %: DC component of HT current immediately after striking spark: 53 mA: 52 mA-1.8 % DO NOT ATTEMPT THIS IF YOU ARE FITTED WITH A PACEMAKER, OR HAVE A HEART CONDITION, OR IF YOU REALLY HATE ELECTRIC SHOCKS. Dual plugs provide both redundancy should a magneto fail, and better engine performance (through enhanced combustion). If the brush is missing or there is only a very short piece in the pick-up, the brush (or part of it) may have come out and dropped to the bottom of the magneto housing. The turns ratio between the primary and secondary coil is selected so that the voltage across the secondary reaches a very high value, enough to arc across the gap of the spark plug. The contact points which are mounted onto the end of the armature shaft, used to time the breaking of the primary winding current, will become pitted and worn, especially so if the capacitor is faulty. 0000006861 00000 n load correctly in the translated versions of the pages. NEW Thanks again. With some magnetos, the main-body earth brush is accessible with the magneto in situ. You should not feel any tingles in your hand. I have seen that a lot on FM mags. The Lucas magdyno and magneto units fitted to all AMC machines after 1939 had Nifal magnets which are not demagnetised by removal of the armature. I tested the HT wire and spark plug and both are fine. If not provided with a safety gap, there is a risk of expensive damage. Contact-breaker Re-installation and Points Setting. It is also used in modern piston-engined aircraft[citation needed] (even though a battery is present), to avoid the engine relying on an electrical system. Oil on the inside of the pick-up is usually indicative of a failure of the magnetos oil seal, in which case the magneto will need a more complete overhaul. %%EOF If your bike runs poorly, backfires at all but idle, stalls out and won't start back when hot, then works again when cool. This disables the magneto to reduce the risk of electric shock and fire. IMPORTANT. All rewound units now have modern condensers and enameled wire. To have the discharge go arc back into the coil itself or the mag housing causes some serious damage. Regrettably, some Acrobat .pdf files might not rebuilding magnetos and of how to extract an I got it back, spun it, sparked. Points and contacts cleaned, and wires tested for continuity. Some original units are still in service today. PA. It uses a Bosch ZA4 magneto (rebuilt about 10 years back) which produces a nice blue spark in the plugs when they are out of the engine. One of the plug caps should give a reading which is substantially the same as the reading you obtained in the internal HT continuity section. The older term "high-tension" means "high-voltage".[1]. Mechanical - Bearings, insulation, washers and shimming the armature. The ratio of turns in the secondary winding to the number of turns in the primary winding, is called the turns ratio. Don't want this buried as I 'm hoping for some possible answers today. On the Lucas magnetos, the spec is to jump a .200 gap at 200 rpm for the slow speed test. We always replace the capacitor during a repair as experience has show us that the capacitor tends to be the most unreliable part. Just to reinforce a point here of something very well done that you did in the how-to: when you're testing a mag like this, ALWAYS have the plug wires hooked up with a gap (or plugs) to ground so that energy has somewhere to go. quality are also available, of the correct Our patented EasyCap is a simple "Colonel fair is fair: if I nail Hotlips and punch Hawkeye can I go home too?". and other magneto parts. When screwed in the head, however, the plugs make no spark. If higher than that, investigate. At any one time, we reckon to xref Great post! further selection that can be reconditioned on 096792012013 - 2020 | Website design by The Net Effect of Sheffield, Website design by The Net Effect of Sheffield. Put a smear of grease on the lobe(s) of the cam. Repeat with clean pieces of petrol-moistened rag, until the rag comes out clean. patterns for shims, gaskets and bearing Also, some pattern contact-breaker assemblies are too large at the fat end and need to be filed or ground to size. With the mag on the engine, there is a spark at all 4 plugs . March 21, 2020 in Technical. No this is the type of stuff I like logging in to see! Do similar tests with the HT lead(s) and the plug-cap(s). Nous Replace if necessary. If your magneto is loosing spark after a short amount of time running, or is hard to start it is most likely a condenser failure. A simple magneto (an electrical generator using permanent magnets) is able to produce relatively low voltage electricity, however it is unable to produce the high voltages required by a spark plug as used in most modern engines (aside from diesel engines). Learn how and when to remove this template message, https://en.wikipedia.org/w/index.php?title=Ignition_magneto&oldid=1150712364, Short description is different from Wikidata, Articles with unsourced statements from January 2023, Articles needing additional references from January 2023, All articles needing additional references, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 19 April 2023, at 18:38. Thanks. Fit the magneto gear to the magneto shaft and finger tighten the nut ONLY until the gear is snug on the tapered shaft. 0000002409 00000 n We shall resume operations as soon as we possibly can. With BTH devices, if the moving point assembly fouls the eccentric pin, the pin will need to be adjusted. Once Fantastic! If you do, then replace the pick-up. replace it with an EasyCap. Armoto LtdRegistered & Trading Address:Unit 26, M1 Commerce Park, Markham Lane, Duckmanton, Chesterfield S44 5HSTelephone: 01246 826667 | sales@armoto.co.ukRegistered in England Company No. that old problem, the deeply-buried condenser In this series of pages, well take you through the main things. 82 23 It uses a magneto and a transformer to make pulses of high voltage for the spark plugs.The older term "high-tension" means "high-voltage".Used on many cars in the early 20th century, ignition magnetos were largely replaced by induction coil . insulators; and timing discs. If I was working on it, first I would want a 5/16" air gap consistent spark minimum from the coil terminal to ground. Still here since 1996 serving BritBike enthusiasts. magnetos available for sale or in You need to be a member in order to leave a comment. Check the state of the tappet and replace if necessary. If the resistance is higher than about 15,000 ohms, it indicates a bad connection. or If your multimeter can measure capacitance, the reading should be within 10% of: 150 nF (0.15 uF) for the C01, C02, C03, C05 and CU/150 EasyCaps; 220 nF (0.22 uF) for the C06, C07 and CU/220 EasyCaps. 0 What else could possibly be grounding this? After 20 miles the ignition is down to zero. Problems rooted in the magneto are sometimes obvious, or can seem like all sorts of other things. or Franaise If the magneto wont produce a spark across a 6 mm (or 4 mm) gap at leisurely kicking speeds, and if youve satisfied yourself with all the other checks described earlier, then it probably needs a more complete overhaul. If you have a plug tester available that adds simulated compression pressure (using air pressure) to the end of the exposed plug while firing voltage to it you will see the more pressure the higher kv the plug needs to fire correctly. if it doesn't jump 3/16" double check the points to see if they are shiny clean the whole face of each point. I forgot about this. With other models, it may be inaccessible while the magneto is in situ, for example underneath. Check that all the insulators are in good shape, and reassemble the contact breaker assembly. Regrettably, some Acrobat .pdf files might detailed support we offer. The wires are copper core with non resistor caps. instructions). As the magnet moves with respect to the coil, the magnetic flux linkage of the coil changes. I have tried both Champion and NGK plugs. is it rebuilt? It's easy! Always good to learn how to check lucas parts, one of the weaker parts of a triumph motor.. Classic Cycles inc. 2199 N. Batavia Suite J. In the right direction (clockwise, looking at the points) and a fairly healthy looking spark should jump the gap from one ht at a time, lead to casing. [2] An ignition magneto also includes an electrical transformer,[2] which converts the electricity to a higher voltage (with the trade-off being a corresponding reduction in the output current).[2]. In that case, it it best to dismantle the magneto to retrieve it. Put a smear of grease on the surface of the cam that engages its housing. To all you guys with Lucas magnetos with problems, get ready to see it fully functional for about $23 shipped, along with a little work in your garage. fitted, the EasyCap becomes a routine service The family of Bijan Ghaisar, shot dead by two U.S. Park Police officers as he slowly drove his Jeep Grand Cherokee away from them in 2017, agreed to settle their lawsuit against the . With Lucas devices, if it fouls the contact-breaker spring, the contact-breaker assembly will need to be removed and the effective length of the spring increased as necessary. with a fixed register in the cam housing and with the advance/retard actuator). There has been requests lately on the board for more tech stuff. Lucas (and most other) capacitors made in the 50's & 60's used a paper dielectric. Any high tension magneto will have way more than 7 ohms resistance on the secondary circuit. Brightspark Magnetos Ltd disclaims responsibility for any information as we can about the electrical equipment With your multimeter set to display resistance and connected to the opposite faces of the circuit board of the EasyCap (and with your fingers touching no more than one side of the circuit), the meter reading should climb up from a low value until it goes off the scale (OL). Photo-sequences of stripping and Grease. These were on older equipment which hadcomplete tune upsthat wentto the field and didn't work more than a hand full or two of times and then they would begin to start hard, no start or run for a short time and shut off then not restart. Take a look at some of the equipment we JavaScript is disabled. wish to make the required puller tool of which is the product of Brightspark Magnetos Ltd's Once the insulation has been broken down once, it often makes it easier for it to be broken down again. Likes: 260. scotland. i have had 3 done here by ed strain that included rebuild with remagnatized body for a little more than $200.00. Comment Guidelines: Do post respectful and insightful comments. By This causes the electromagnetic field in the primary coil to collapse rapidly. When screwed in the head, however, the plugs make no spark. I would be interested to hear from people who either have seen this running or know of similar setups in forges. Since the beginning of World War I in 1914, magneto-equipped aircraft engines have typically been dual-plugged, whereby each cylinder has two spark plugs, with each plug having a separate magneto system. sequences illustrating the importance of Links to other service providers can be found This disables the magneto to reduce the risk of electric shock and fire. With larger gaps, if the magneto is provided with a safety gap, the spark is more likely to jump there where it cant be seen, so thats a waste of time. If necessary, dress the points on a fine stone. Post in the forum instead. Deutsch 0000000783 00000 n An importance cause of field strength reduction is the removal of the magnet from its normal situation without fitting a keeper, a device designed to maintain the integrity of the magnetic circuit.