LCGB Forums

Broke down on way to work this morning. No spark.
Will strip later to check. Tried plug and cap at roadside.
I have a spare stator and CDI at home, but is the new Lukas CDI a better option, just run it off my lighting coils if the LT Coil has failed.

Are these supposed to be get you home devices or use at all times?

Did you take the green wire off the cdi?
Should be two green wires,take the one that comes from the loom off.
If it starts then its probably the cdi thats u.s..

roli150lam wrote:Did you take the green wire off the cdi?
Should be two green wires,take the one that comes from the loom off.
If it starts then its probably the cdi thats u.s..

Why the CDI if you bypass the loom ?

Taking off the green only rules out an ignition problem at the switch or cut out or anywhere in between not the CDI.

Oops should have added a "not" in there.sorry.

If you have a new CDI,try that.If it works then its your CDI thats at fault.I am running my scooter from the Lukas CDI via the lighting coils,if the new CDI works then you will need to buy a new one,the Lukas CDI is more expensive than a Ducati one but cheaper and less work than renewing your stator plate and CDI,the Lukas CDI fits in the toolbox and if the LT coil packs up whilst your out riding and you suspect that to be the cause,at least you'll be able to ride home using the Lukas CDI.

Agreed, lighting coil failure is a lot less common than LT coil failure because of the thickness of the winding wire.

Don't get me wrong, I love reliable stators with good LT coils but the majority of cheap stators have questionable LTs.

Adam

LT coil failed. Reading 50 ohms.

This is my 3rd BGM LT Coil as well as having two BGM stators fail pick-ups as well.

Appreciate that Lukas wont help my previous pick up failures. Think I'm going to stick a Scooter Restorations Indian Stator in next time around when the engine is next out.

Paul_from_Thornbury wrote:LT coil failed. Reading 50 ohms.

This is my 3rd BGM LT Coil as well as having two BGM stators fail pick-ups as well.

Appreciate that Lukas wont help my previous pick up failures. Think I'm going to stick a Scooter Restorations Indian Stator in next time around when the engine is next out.

If you have 5 of them kicking around repair them? Tend to find BGM ones fairly reliable. Haven't had one go due to LT or Pickup in a couple of years.
What has happened is the rivets have come loose on one! And the stator fixing bolt came out and jammed up solid.

I've just fitted an external pickup which should mean quickly back on the road should the normal one fail. Wonder if having one of those Lukas CDI's wired up along side a normal one would mean a completely bullet proof ignition system all ready to go. A back up for every item that can and does fail, Pickup, LT Coil, and CDI.

I have known LT coils to fail,but I've never heard of a case of a pickup failing,although it must happen,its just that I have not heard of one

HxPaul wrote:I have known LT coils to fail,but I've never heard of a case of a pickup failing,although it must happen,its just that I have not heard of one

I've replaced 2 pickups on BGM stators, and replaced with genuine Ducati items....

Paul_from_Thornbury wrote:.............Are these supposed to be get you home devices or use at all times?

They are a permanent replacement for the LT coil. The system taps into the AC lighting coil output, rectifies it to DC to provide the voltage for the spark. A better system is available from Anthony Tambs (Scootronics on FB), his CDI will run AC or DC using either the normal pickup or one of his external pickups. For dc operation you can either take a feed off the lighting or if you have a fully DC system it will work from the battery voltage.

If you are looking for a high quality stator then I'd also recommend you have a look at the Scootronic ones which are about the same price of the BGM but with extended slots for adjustment.

I'd like to know why you think the Anthony Tambs CDI is better than a Lukas.I have both a Lukas and an Anthony Tambs CDI,one on a series 2 and the other on a series 3,so I dont have a preference,I'm just curious.

Lukas fitted. Yellow wire from Stator and yellow wire from Lukas on Regulator 'IN' as shown on Reedspeed diagram.
Black from BGM regulator and Lukas to earth.
Red from Stator to Lukas.

That's the minimum needed to get it started....but No spark...now I'm stumped

Reedspeed diagram is wrong. It shows Stator yellow and Lukas CDI on same input to regulator. This is wrong. Stator on input and Lukas on output is correct.
See new post however, as now operating the horn cuts out the engine.

Paul_from_Thornbury wrote:Reedspeed diagram is wrong. It shows Stator yellow and Lukas CDI on same input to regulator. This is wrong. Stator on input and Lukas on output is correct.
See new post however, as now operating the horn cuts out the engine.

There is a slight downside to the Lukas when powered directly from your lighting coils.
You do need a good output from the generator at tickover to power the CDI especially with engines that enjoy a really low tickover speed. Turning on the lights or operating the horn can kill the ignition with non battery setups.
A better way is to use an old 6v Ducati points stator that has been correctly rewired for 12V operation and fitted with the electronic reluctance pickup from a modern electronic stator where the points used to be.
The original LT coil can now be used to power the Lukas without it being affected by the lights and horn.
I suppose you could try it the other way around by taking the LT coil from the 6V plate and fitting it to the modern 12 electronic plate. I've never tried this and so cannot comment on any foibles that it might throw up, but its worth investigating.

I think that the BGM pick-up's are a bit suspect.....there have been 4 failures on this page alone.

I find duff ones from all sources and they almost always measure ok resistively, which is very frustrating. I find the only guaranteed way of confirming a proper signal from the pickup is to measure it with an oscilloscope. This makes it easy to check correct alignment of the pickup with the flywheel. If it is misaligned then the positive going pulse will be stronger than the negative going one, or visa versa.

On an associated matter, I am in the process of fitting an Anthony Tambs CDI and HT coil to my scooter, but I will not be taking the traditional CDI/HT box off. I will keep this, with the HT lead and spark plug, fixed on the scooter for quick fault-finding at the road-side.

There is never a good time to be stuck at the side of the road, and every minute counts if you are stuck in a dangerous location.