Bonneville America Forums Forums Off Topic Discussion Forums Lounge Lucas electronics: A question for you old timers

Was reading a story about a company restoring old XKEs and they replace all of the Lucas Electronics. Over the years, I've heard negative things about electrical parts from Lucas. Whats the story? Also does Triumph use them?

Well Eddy, the major issue with the old Lucas electrical systems was that once the smoke escaped from the wires, they were no longer any good!

(...GAWD, I love that old joke!!!!)

Yep, actually, just about all older British cars and motorcycles used electrical systems manufactured by Lucas, and they didn't have the best reputation around. Some of the issues stemmed from the use of a "Positive Ground" type of setup, while other issues were for the tendency of their voltage regulators to fail, and thus causing the wiring to fry...hence that old joke about the "smoke", which also could be caused by the older Lucas practice of making a wiring loom by bundling a number of wires together and using a shellac, which over time would dry and crystallize the wires and thus making them brittle.

And no, from what I've read, modern Hinckley-build Triumph motorcycles do not use Lucas-built electrical systems. I believe I've read somewhere that Triumph outsources those components from some manufacturer in France.

(...yeah, I know, "France"...that doesn't sound like much of a step up from Lucas, does it?!)

Thanks Dwight. Over the years, all I've heard was to watch out if something had Lucas Electronics. Specific reasons why were never given only that they were unreliable.

I like Lucas electrics, the weak spot was the harness. The Zener diode was not the best regulation method either. The Magnitos in many cases worked for 50+ years if maintained. Problem with those was they put the condenser inside the armature so when it did finally go you had to rewind the armature to replace it. The alternating current generator used later from the late 50s on was very dependable similar to what we have in our bikes now. You could let the battery go completely dead and a kick or 2 would still start the bike since no battery was needed to produce current with the large fixed magnet on the end of the crank inside the stator. Just spin it and you had power. I loved the dual point set up too, very easy to fix if you had any ignition problem along the road. Lucas has now made a better replacement point plate for those bikes with really good quality points. I used to carry a breaker plate with points on it in a tin in my tool bag and a timing tool and feeler gauge. To time it there was a hole at the base of the jugs that you threaded in the timing plunger. Early Triumphs had a hole drilled for TDC that that plunger located with then you used a degree wheel to set the timing to 32º BTDC later (67 on if my memory serves) models had 2 holes in the crank for that plunger and one was firing position. You turned the crank past that then backed it up to the hole to take up any lash and then set the points fully advanced. There was a fix for the Zener diode called a Typanium unit that replaced the diode and rectifier and worked better. I always did and still do run the stock electrics on my old Triumphs and have never been left sitting along the road. I have had occasional problems but always fixable with a few simple tools. I wish there was a conversion kit to go back to that for our bikes instead of the CDI we have to pay through the nose for now and can't fix along the road. Same with a kick starter, wish we had one of those too incase the battery runs low. If I had to replace the entire ignition on my old bike it might run me around $100 to $150 vs. the $500 just for a CDI now and the old ignition chances are all would need to replace would be a $9 set of points. The old Lucas electrics were very reliable if you rewired them yourself. I used to run a simple 5 wire harness eliminating the extra crap you didn't need with soldered connectors vs. the old connector where the wire slipped through the connector and was folded over then plugged together. Bad connection waiting to happen. Lucas components were excellent.

Nothing wrong with Pos. ground systems and they even inhibit corrosion. Not only Lucas used it but many manufacturers used to use it. My Studebaker has a pos. ground system and it is still all original parts that were put in that car in 1955. Nothing except brushes have ever been changed, the harness and components were all put in that can at the factory and are still there. The magnito on my 1958 T-110 Triumph is also the original unit that has never been rebuilt, that is also working just fine.

The other old joke was...Why do the British drink warm beer?

Because Lucas made the refrigerators.

Well eddie, while Ian here might have a few valid points(especially about these darn CDI units on our modern Triumphs which have a less than stellar reputation), just remember one thing, you're hearin' about the "glowing" reliability factor of Lucas Electronics of old from a guy who still wishes the boys in Hinckley would've put a KICKSTARTER and an old style CONTACT POINTS IGNITION SYSTEM on these here modern bikes of ours!!!!!

(...and he just LOVES carryin' that little piece of sandpaper around with him whenever his old Triumph's points need to be cleaned up a bit out there on the open road...RIGHT Ian?!)

Correct sir!

Also.... Lucas , prince of darkness .......

True story,,,few years back in a Golden Corral,,, buddy and I (in power-pirate attire)were joking about our old Brit bikes and Lucas , prince of darkness.....scarred a patron, kid went to the manager and we were then asked if we were devil worshipers (making his customers uneasy refering to the old prince);-) manager turned out to be an old BSA rider and when we explained .... ha !

My T-shirt I have on today reads.. LUCAS MOTTO
BE HOME BEFORE DARK..
but really .. if the old harness was kept complete and clean ..very little trouble .. the connectors were a bit small.. and could be a problem.. overall the only time I had real problems was w/ a less than stock harness.

I'm sure most of us Old Timers ... can remember at least one dark night when all went black at the worst possible time.. those are the things that will bring a smile and another story ..

i kinda feel the same as Ian, i have a 72 that has only ever needed points once in awhile, i miss the kickstart as i would like to have both on my new America. but yes, i have changed a few sets of points on the side of the road(so to speak) but the diode?? never gave me any problems except in the rain, that bike hates the rain that bike is still original and thru the yrs i have heard a lot of things about lucas and i have seen friends with nightmarish problems with the electrics but i guess i just got lucky when i got mine, she has 112k miles on her and like i said, points?? yep other electrics?? nope. but i had a norton once that i cant say that about

Appreciate the responses. However, since I'm not a wrench, I'll stick with the modern technology. Oh Boy! Flash backs of a scrawny little kid trying to kickstart a flooded out Yamaha 80.

As most of you know I have quite a few Triumphs and they all have stock electrics and the only issues I ever had were the harness and points now and then. I had 1 diode short on me that cooked that part of the harness but easily fixed with a couple wires and a new diode. If there were conversion kits like HD used to make for their stuff I would do it in a heart beat. Points and a kicker! don't I wish!

With Ian on this one. You could fix your bike on the side of the road and having the kick start was a god send especially as the batteries back then were not that great. Rode with a few guys back then that had early Dukes and they had a lot more troubles than the trump with electrics.

Imagine how scared the astronauts were when a tag on the overhead console fell of and it said Electrics by Lucas.

I remember the biggest problems we had was frying wires with grounding problems.

MOst of the problems with Lucas stuff was that it was slightly different than what we made and guys didn't take the time to learn it. Positive ground being one. I've had a few old trumpets, and any one that I rebuilt with stock electrics never had any problem. I have to confess that my eyes glaze over when the young guys talk about the new electronic stuff, I just haven't kept up.
Another potential problem with the wiring was that the bikes and cars were shipped over in regular crates and plats. (the japs started plastic wrapping their stuff) The salt air on the trip over could wreck havoc on the connections it they sat for a long time, which they often did before sale. Just one theory I heard. I'm with Ian, though. Give me a set of points and a kickstarter anyday.

I drove an MGB for a year or so. I spent at least twice as much time working on it as driving it. Electrical, suspension and carburetor problems mostly. After growing up with AC Delco Lucas was just strange.

Fred Lucas,AKA "The Prince of Darkness"

Only problem I had with my old '49 Triumph was the selenium rectifier. This was not really the fault of Lucas though because theirs were hard to get so I used the 5 amp ones from a TV parts supplier. Positive ground is a good thing. It is scientifically correct because electricity flows from - to +. The reason there was a universal change to 12V - ground in 1956 was to change to transistor radios. Seems that the technology at the time favoured transistors that require - ground.

At an antique Brit bike event, one vendor claimed the problem with Lucas was that Triumph forced them to make everything as cheaply as possible. I have no clue how true or false that may be.

On another note, Lucas' fuel injection systems are considered by many to be among the finest anywhere. Don't know much about that either.

As far as the new ignitions go, when they're done right - There's a 15 HP Kawi powered lawnmower at work. One pull, year 'round. A 90 year old lady speed pull will do.