LCGB Forums

Just finished my restoration

viewtopic.php?f=19&t=4850

It's original flywheel etc and points/condenser and runs really nicely, but in this set up what acts as a regulator?
Just been playing round the block (not yet registered) and I seem to have blown the tail and dipped beam lights. My hazy memory thinks that one of the lights (speedo or the parking ligh) acts as a kind of soak for any overload. I may just have imagined this, so what causes/stops bulbs blowing under high revs.

cheers steve

I think the speedo bulb is supposed to be 12v instead of 6v thats the theory .
When I had 6v on my Li, mine used to blow stop /tail bulbs.
I put a 12v bulb it never blew again .
However I managed to kill the ancient 6V electrics not long after going nearly flat out on the bypass.
I ended up putting a re-worked 12v system from Beedspeed after taking sound advice from Hxpaul.
Never had a problem since with blowing bulbs

someone once advised me to fit something called a zener diode.not sure that is spelt right .which I was told would stop blowing bulbs on a 6v system.never got round to doing it but I believe they are very cheap and maybe some one wiser will come on with some details ,if this is any good or not.

Post by Stevepshipley » Sun Nov 20, 2016 3:12 pm

Just finished my restoration

viewtopic.php?f=19&t=4850

It's original flywheel etc and points/condenser and runs really nicely, but in this set up what acts as a regulator?
Just been playing round the block (not yet registered) and I seem to have blown the tail and dipped beam lights. My hazy memory thinks that one of the lights (speedo or the parking ligh) acts as a kind of soak for any overload. I may just have imagined this, so what causes/stops bulbs blowing under high revs.

cheers steve

I think you may have been thinking of the practice of fitting a clipper diode to rear lights.

If you search on line, one Forum or another should give you more information.

I hope that helps...

I had the same problems a while ago as well as in the 80's when Lucas clipper diodes were available. Not wanting to go electronic I persevered with the 6 v system but found several coils kicked out far too much voltage so I swapped the coils off a Vespa 12v stator and fitted a BGM regulator. I'm sure I saw that BGM ? also do a 6v reg so maybe you could fit one in the circuit to limit the voltage.

There must be loads of 6 volt rectifiers knocking about from all of those that have converted to the 12v electronic systems.

Did you mean rectifier or regulator WT1?
I don't know what a rectifier does?
Cheers steve

Post by Stevepshipley » Tue Nov 22, 2016 12:15 am

Did you mean rectifier or regulator WT1?
I don't know what a rectifier does?
Cheers steve

Both!

Terminology, eh?

It's the standard kit for Lambrettas that rectifies/regulates the supplied power down to a known DC quantity to enable battery charging, amongst other things.

I believe that all large frames have provision for it to be physically fitted although the wiring may need modification. Of course, not all frames have a battery tray, either.

However, my point was that there must be hundreds of these knocking around with so many owners converting to the reliable, oh-so-well-balanced, heavyweight, Indian electronic systems.....

Oh! Almost forgot! Apologies to anybody that notices we're still 'on topic'

Thanks WT1

Sorry Steve.

I’ve only just realised the association with that lovely GP125 in “Show your Ride”

Of course you won’t want to meddle with what you have for the sake of originality, but there may be other options.

For a start, the speedo bulb should definitely be 12 volt, possibly as a means of excess voltage soak(?), but it is a fact that otherwise they are too bright.

Thinking laterally, apparently, there are/were 6 volt motorcycle specific bulbs. They tend to have an extra ‘leg’ supporting the filament. It might be vibration rather than overload that's making them blow. Perhaps the bulbs that blew are not quite as fresh as, say, your recent head wound? Sorry...

Lastly, the clipper diode was an effective cure, apparently, for modified, higher revving motors to stop the rear bulbs blowing & I reckon there is a modern day equivalent. I just don’t know what it is but a search on old motorbike Forums will help if nobody on here can.

Good Luck!

The headlight bulb should be 6V 25W/25W. A 35W is too dim. For when you do get around to riding it in the dark....

I can recommend the small BGM size regulator for anyone wanting a decent regulator. They are available as 6v and 12volt as my friend Snails found out on his Lue. He had bought a 6 volt unit by mistake and had it on a 12 v system wondering why his 12v lamps were dim. Basically the regulator was doing its job clipping if you like the high voltage to 6 v. They all have the extra terminal to trickle charge a battery of whatever flavour.. but just leave it unconnected if you don't have one.
I have fitted these into the old original regulator box soldering the wires to the standard terminals so the box looks and connect as an original one but with modern electrickery. The Lucas Zennor can still be used but they all do the same thing.
If you go this route you won't need the 12v speedo lamp as the regulator will do its job.

Ok just to close this off (I hope),

Many thanks for the input. I didn't "blow" the rear bulb the lead had become loose and I think the subsequent surge caused the front to go.

Anyway, all back together and sorted for now, 12 volt speedo bulb so I'll see how it goes.

Cheers all - Steve

12 volt speedo bulb so I'll see how it goes.

Exactly as Innocenti intended.

Besides which, a 6 volt bulb is much, much too bright, especially bearing in mind that we want to encourage youngsters on to the scene, not scare them off with the sight of open face helmets with glowing dentures....

Just looked at your scoot on the other thread .

Santa has been early hasn't he

The scoot hasn't got a battery fitted so it won't have been fitted with a rectifier or a regulator .
Your Stator lighting coils generate an AC voltage which feeds your AC bulbs and horn directly which is why your lights increase in intensity as your revs rise and dim into oblivion when at idle.

if you want to fit a battery you'll need to find somewhere to fit one . they are usually fitted on the non-carb side in front of the air tank .You'll need to fit a rectifier which rectifies your existing AC voltage into DC (direct current) voltage so that it can charge your battery and a Regulator which makes sure that the battery doesn't get overcharged . They are usually in a combined module for convenience but don't necessarily have to be .Naturally if you do this you will need to change all your bulbs to DC whether 6v or 12v and probably the horn as well

I would look for a Vespa regulator/regulator they are modern and easily obtainable and whilst you are there I'd advise anyone to fit a PX200 Vespa coil as well. much better than the lambretta jobbie.

Am I allowed to say the word Ve**a ?

johnnyXS wrote:Just looked at your scoot on the other thread .

Santa has been early hasn't he

The scoot hasn't got a battery fitted so it won't have been fitted with a rectifier or a regulator .
Your Stator lighting coils generate an AC voltage which feeds your AC bulbs and horn directly which is why your lights increase in intensity as your revs rise and dim into oblivion when at idle.

if you want to fit a battery you'll need to find somewhere to fit one . they are usually fitted on the non-carb side in front of the air tank .You'll need to fit a rectifier which rectifies your existing AC voltage into DC (direct current) voltage so that it can charge your battery and a Regulator which makes sure that the battery doesn't get overcharged . They are usually in a combined module for convenience but don't necessarily have to be .Naturally if you do this you will need to change all your bulbs to DC whether 6v or 12v and probably the horn as well

I would look for a Vespa regulator/regulator they are modern and easily obtainable and whilst you are there I'd advise anyone to fit a PX200 Vespa coil as well. much better than the lambretta jobbie.

Am I allowed to say the word Ve**a ?

Never heard of ac or dc bulbs.You'll definitely have to change the horn.

HxPaul wrote:[
Never heard of ac or dc bulbs.You'll definitely have to change the horn.

do a google search

Both AC and DC incandescent bulbs will work on AC current but the original bulbs on the early non battery Lambrettas were AC type

All scooter/motorcycle and car shops just sell bulbs,they dont specify wether their ac or dc.If your saying that ac and dc will work with both battery and non-battery systems,whats the point of having 2 different kinds?

No such thing as an Ac or DC lamp. They are just lamps (bulbs if you prefer).

It is different with LED, but we're not talking LED, just incandescent lamps.

Those made by GEC tend to be better quality than those made by Ring.

HxPaul wrote:All scooter/motorcycle and car shops just sell bulbs,they dont specify wether their ac or dc.If your saying that ac and dc will work with both battery and non-battery systems,whats the point of having 2 different kinds?

I don't know Paul . why don't you do a search on google .

All the light bulbs in your house are AC