I do not know it all but I will try to help. 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. capacitance to satisfactory ignition system grade to avoid carbon deposits on the slip If possible, get somebody to help. Joined: Oct 2009. Now line up your degree wheel with the pointer at 38*. With the Lucas KN1, it is under the identification tag. I'll try the 3/16" gap test. 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. Checked it over and found no spark. NEW These faults do not necessarily occur instantaneously, they may develop over time leading to a gradual deterioration of the spark output. Some have both types of earth brush. 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. Language links are at the top of the page across from the title. Powered by Invision Community. or. Twirl the armature. Lucas Magneto 1930 - 1940. demand to 'perfectly functional' or 'as-new' If it is an original capacitor then it will almost certainly fail because of its age and the materials and techniques that were used to construct them. V-TWINS Magnetos are always a compromise, usually producing a strong spark to one cylinder and a weaker one to the other. It is almost a given that a Lucas armature will require replacement if in the original condition. A capacitor is placed across the points which absorbs the energy stored in the leakage inductance of the primary coil, and slows the rise time of the primary winding voltage to allow the points to open fully. Brightspark Magnetos is now able to offer a remagnetising service, using our specially-developed remagnetising and measuring equipment to help you restore your magneto to tip-top condition. Reassemble and check operation. 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. You should not feel any tingles in your hand. part-exchange. 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. After you get your spark strong enough, then worry about cap and rotor. Click on a button to see magnetos from other manufacturers Bosch BTH Others Click on any picture to get a larger view Capacitors, which are short-term storage devices, often fail in older magnetos due to dielectric degradation (short circuit) or conductor breakage (open circuit). This can mask a fault on these cars as the vehicle will continue to run until the other fails. If you can see the slip-ring through the pick-up hole in the main housing, check that the brass ring or segment of the slip-ring is brass coloured (albeit possibly a bit dirty or tarnished), but not completely black. 85 0 obj<>stream On more advanced magnetos the cam ring can be rotated by an external linkage to alter the ignition timing. 0000001015 00000 n Fit the magneto gear to the magneto shaft and finger tighten the nut ONLY until the gear is snug on the tapered shaft. books, learndpapers and patents on Remove the pick-up(s) from the magneto taking care not to mislay the gasket(s). If there are any, replace the pick-up. After 1 hour or so the bike can be started again, but the ignition fails again after riding about 20 miles - not a pleasent way to ride! Comment Guidelines: Do post respectful and insightful comments. We also provide If there are any, repeat until the paper comes out clean. If the reading is less than 3000 ohms, it would be unusual, but is indicative of a problem. If the magnet is full strength and the spark at the points looks right then I would still say you have a coil problem with some shorted turns or something. A good Wico X series mag will jump at least 3/8" air gap. Housings can sometimes get misshapen, in which case try to rectify that. Nous Thanks. The coils are, of course, designed for this pressure but no insulation is perfect. [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. specially-selected, top-quality, British-made Trouble starting my 1924 Citroen engine. The result in high resistance will reduce the current flow in the primary winding and reduce the magnetic flux which adversely effects the secondary winding output voltage. 0000005012 00000 n Thoroughly clean the pick-up using a rag moistened with petrol. Contact Us - DO NOT EMAIL CAR QUESTIONS. Great write up, with video even! English He got it and thought the ring the points rides in came out and just needed pushed in. We always replace the capacitor during a repair as experience has show us that the capacitor tends to be the most unreliable part. NEWS FLASH - March 2020 As you will understand, with the Covid-19 pandemic shutting down most normal business, we are not able to despatch orders for the time being. I have seen that a lot on FM mags. If not free to move, ease it. Because the magneto has low voltage output at low speed, starting an engine is more difficult. 0000001320 00000 n 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. but enjoy doing it, with confidence, relying on the On the Lucas magnetos, the spec is to jump a .200 gap at 200 rpm for the slow speed test. I know a great starting engine will fire a plug with 3/16" gap when external of a cylinder. 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 air gap between the rotor and the cap actually increases spark output as long as it's not excessive. Our patented EasyCap is a simple The engine needed some attention, which it has now received, but I had to take the magneto off. Under construction, so far showing video It should fit properly in only one precise position. For a better experience, please enable JavaScript in your browser before proceeding. dynamos, regulators, alternators and the brass is in the wrong place, as a result of a magneto with a segment-type slip-ring having an incorrect cam fitted or having the wrong direction of slip-ring fitted. 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. Do not skimp on quality with pick-up brushes. To have the discharge go arc back into the coil itself or the mag housing causes some serious damage. Great post! Measure the resistance between the magneto body and terminal in one and then the other of the the plug caps. The readings for the two plug caps should now be swapped around. If everything were perfect and clean, the resistance should be infinite (OL). Links to other service providers can be found 0 quality are also available, of the correct Links to some interesting Replace if necessary. Svensk This was diagnosed as the cam ring not being properly timed to the magnetic poles. many ignition systems, focusing especially on slip rings and pick-ups for Lucas and BTH anglais, votre convenance. Check that the felt pad in the end of the screw holding together the two blocks of the points assembly is present and good, and soak it in oil. A Italiana You are using an out of date browser. Espaol Having removed the contact-breaker assembly from the magneto, disassemble it, noting where each part was. Problems rooted in the magneto are sometimes obvious, or can seem like all sorts of other things. 0000005468 00000 n I got it back, spun it, sparked. The original coil may be reusable, although it is susceptible to faults - as described in our section: common problems on magnetos. JRC Engineering Inc. 3110 Indian Ave Unit 1E, Perris, CA, 92571. Nice work. That then produces a gap of about 4 mm between the centre electrode and the screw-threaded bit of the plug body. If they look good I would replace the condenser if it has one and retest. However, provided the reading is more than about 500 ohms, it is probably OK. We can adapt for most applications. The reading will probably be a fraction of an ohm. If necessary, dress the points on a fine stone. Also, some pattern contact-breaker assemblies are too large at the fat end and need to be filed or ground to size. Lister D Magneto Lucas RS1 full rebuild but still no spark Coil Fail. So, re-check everything in the contact-breaker assembly first before deciding on a more complete overhaul. ring. Wico-XH Magneto Won't Spark | Smokstak Antique Engine Community 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. 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. magnetos. At any one time, we reckon to Magneto coils are usually a long time dying. 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. And a f-ing video! 096792012013 - 2020 | Website design by The Net Effect of Sheffield, Website design by The Net Effect of Sheffield. The irony here is that usually these magnetos fail to spark. Regrettably, some Acrobat .pdf files might not Excellent "how-to". If I was working on it, first I would want a 5/16" air gap consistent spark minimum from the coil terminal to ground. With a twin, repeat with the other pick-up. "Colonel fair is fair: if I nail Hotlips and punch Hawkeye can I go home too?". The other plug cap should give a reading that is infinite (OL) or extremely high. here. When we undertake the renovation of these magnetos, we examine the following:-. These are prone to deterioration and the cause of many ignition faults. So I'm having an issue that is frustrating me and my mag rebuilder. 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 . Norsk I wonder if hand-cranking might get it going. -- Tickover, pulling away, and low-speed running erratic. asked questions, some of which isn't to be Not sure what came off, but 1930s/40s I would have thought.prefer collection, but would post. Voltage across the primary coil results in a proportional voltage being induced across the secondary winding of the coil. 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. A forum community dedicated to Jockey motorcycle owners and enthusiasts. 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. A small number of electrons is ever present and over years or decades this flow carves out an ever widening pathway through the insulation. Upgrade your membership to 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. The plugs are non resistor, gaped at -025", and are new. I did notice a very small spark between the contact breaker points. If you have a Megger or similar insulation tester, set it to test at 500V. Some original units are still in service today. The condensers we get now are made in area's that there are no or very poor quality control checks. 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 % As the size of the combustion chamber determines the time to burn the fuel charge, dual ignition was especially important for the large-bore aircraft engines around World War II where it was necessary to combust the entire fuel mixture in a shorter time than a single plug could provide, in order to build peak cylinder pressure at the rpm desired. We shall resume operations as soon as we possibly can. Thank you for your patience. rebuilding magnetos and of how to extract an %%EOF IMPORTANT. Make sure they are there and can move in their holders and give them a good clean. Nederlandse When screwed in the head, however, the plugs make no spark. -- misfiring, particularly at higher revs and fully open throttle, or when opening the throttle. Lucas magneto problems? NEW CHEAP solution to bad condensor Lucasworkshopinstructions-magnetosLucasworkshopinstructions-otherstuffLucaspartslistsLucasATDspecificationsBTHinstructions&partslistsM-LBookletsMagntoFrancedocumentationRobertBoschDocumentationAmericanBoschworkshopinstructionsPatentsBooksandlearndpapers, Redesigned contact breaker for ring cam models, SR1, SR2 & SR4 magnetos (workshop 0000006861 00000 n On the very first BSA I ever owned, I sufferred the same problem. degrade with age. i found that is a cheaper, easier way to go than doing it my self with refurbished parts. With the earth brush(es) now replaced, measure the resistance between the back-plate of the contact breaker assembly and the main body of the magneto. Put a smear of grease on the surface of the cam that engages its housing. The gap will widen as the wire ends melt further apart and soon the adjacent turns will be affected so the coil will eventually fail. If sloppy, consider fitting a new moving point (Lucas), bush (BTH), or pivot post. 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. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. You can check the latter by removing the pick-up(s), rotating the armature in the proper direction until the points are just opening, and checking that the brass is visible directly underneath the pick-up hole (or one of the pick-up holes) in the magneto body. <]>> I pulled my B34 out after the winter and could not get it started. Photo-sequences of stripping and Take a look downloadable drawings for those of you who Timing Lucas K2F and K2FC Magneto | Jockey Journal Forum Posts: 34. Clean and grease the moving-point pivot. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. All rewound units now have modern condensers and enameled wire. I also needed a new coil for it which I installed, cleaned the mag up and replaced any bits it needed. not load correctly in the translated versions of the pages. We also sell our Brightspark range of Lucas (and most other) capacitors made in the 50's & 60's used a paper dielectric. Lucas Magneto Bearing Shim Pack 15mm | E15 | N3048 | K1F | SR | K2F . Gift Article. making your own bearing and slip-ring pullers; Wrap some rag around the end of a stick about 1/4 diameter, moisten it with petrol or other cleaning fluid (but not so much that it is dripping), poke it through the pick-up hole in the magneto body, and rotate the armature to clean the slip ring. 5.5 mm (220 thou) THREE-POINT SPARK GAP. (Chinese) 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. further selection that can be reconditioned on 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. An ignition magneto (also called a high-tension magneto) is an older type of ignition system used in spark-ignition engines (such as petrol engines). If your bike runs poorly, backfires at all but idle, stalls out and won't start back when hot, then works again when cool. Common Faults on Magnetos LUCAS Magneto check "How To" - Jockey Journal Forum the brush spring is not touching the terminal in the pick-up holder; the connection between the cable and the pick-up is corroded; the screw in the plug cap has gone down the side of the HT cable and not down its centre; Slip-ring Lucas workshop instructions - magnetos The timing marks should not wander with the RPM of the drill. [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]. Dual plugs provide both redundancy should a magneto fail, and better engine performance (through enhanced combustion). 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. Even if the points surfaces look good, clean them with fine emery cloth to remove any oxide layer. A short circuit absorbs all the power, hence no output or spark. If it does not jump 3/16" it probably will not fire a cylinder under compression. Come join the discussion about performance, restorations, modifications, classifieds, troubleshooting, maintenance, and more!