Technical help for Series one, two and three Lambrettas. Models include the Li, Li Special, TV, SX, GP, Serveta and API/SIL models
by eyeguy » Sun Oct 08, 2017 7:59 pm
I'll try to give enough info to describe what I have done. First the problem is dim brake lite when headlight is on. all goes dim. when headlight off brake light works great. Li 125 with original junction box. All connections seem good with OHM meter. Original HT coil. The wire loom new. Bulb holder NOS. Ground is good from rear to front. Speedo lite has ground to Rod bracket. Also instead of ground on headlight it is also grounded to rod bracket. Power coming from stator has a strong 9 to 10v at revs. I also got a brake light rated @ 3/15v according to original. front bulb is still 25/25v. I understand it should be 18/18v, can't find. light switch brand new. I have all connected properly. Again brake light works good when switch off. I know it's pulling from somewhere but at the end of my limited knowledge. Also the scooter starts on second kick and runs without fail.
Hope this is enough info
thanks
eyeguy
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eyeguy
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by Meds » Sun Oct 08, 2017 8:14 pm
Check to see if you have mixed up the brake light and back light feeds. So that the back light feed is illuminating the 15w filament and the the brake light illuminating the 3 w filament.
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Meds
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by eyeguy » Sun Oct 08, 2017 9:10 pm
Don't want to sound dumb, but is the larger filament the 15w? I know on the holder one side is pink. thats where the pink wire is.
Thanks
eyeguy
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eyeguy
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by Hornbyfrog123 » Mon Oct 09, 2017 6:15 am
You could change the rear lights for simple led types, you will need to make new bulb holder, piece of mirrored metal cut to fit in lens and them drill for rubber mounts for 12w5v push in bulbs. Then think about replacing rectifier (Cam Lam £7.50 are ideal) this should a: give you a better head light 2: make rear lights and brake light better.
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by Tractorman » Mon Oct 09, 2017 8:39 am
Is your system 12 volt or the original 6 volt? If it is still 6 volt I don't think you can get led's that work on 6. The brake light take the higher value side of the bulb. You may what to consider changing to a 12 volt system if you want better lights.
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Tractorman
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by eyeguy » Mon Oct 09, 2017 12:16 pm
I have considered the 12v system. Presently 6v. Did this system not work when they were new? Find it hard to believe if it did we can’t get it to work today.
Thanks
Eyeguy
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eyeguy
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by Tractorman » Mon Oct 09, 2017 6:13 pm
Yes, my series 3 150 had lights when it was new but they weren't brilliant. The was of course a long time ago and things like stator/flywheel out put deteriorate. Get the flywheel and stator checked out it could be that.
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Tractorman
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by MickYork » Mon Oct 09, 2017 6:17 pm
If it's the original 6v flywheel it may need re-magnetizing.
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by eyeguy » Tue Oct 10, 2017 6:37 pm
I found the post here about using a vespa regulator to convert to 12v system. Does anyone know if the one i found is correct[see pic] also the diagram that was posted is a little confusing to me. maybe someone could make a simpler one that would match the color wires coming from my stator which are BROWN BLUE GREEN. If the pic of the regulator doesn't come through please visit scooterwest.com type in PX Euro 12V AC/DC Regulator. not good at electrics. some knowledge.
Thanks for all the help
eyeguy
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by davla » Tue Oct 10, 2017 7:01 pm
Personally I wouldn't bother with LED rear bulbs, I've tried them but found replacing the rear light cover, bulb holder & reflector and bulb gives a nice bright light. I'd hazard a guess that your flywheel needs re-magnetising but even then I don't think it' will ever be as good as a 12v system IMO
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