LI 150 Special - Brake light OK but no running light - HELP

[grandpa]

Hi Harps2
Have you actually put a meter on ac and checked that you have 12 ac at the black wire in the bulb holder when the lights are on.
1. With engine running put meter probe on black wire that's plugged into headset junction ( other probe on chassis)do you have 12 volts try and put probe on actual crimped connector if yes go to black wire at rear lamp ..do you have 12volts with meter probe on bulb holder contact when it is pressed in?,if yes something wrong with bulb or earth.
2 examine the crimping at both ends ideally solder them.You can have connectors crimped on the insulation but not touching wires, flex the black wire as you are taking readings (an analogue meter is better for fault finding.)
WT1 has a good point in fitting another earth to also eliminate the ground return
You are almost there.
Grandpa

[harps2]

NEW PROBLEM
Scooter now refuses to start so cant get on with Rear light problem ..........................................

Things done to date:-
Checked timing, points gap, (cleaned points with emery paper) OK
Checked green wire from stator to earth wire - reasonable spark OK
Checked all connections from stator to junction - OK
Checked all connections in headlamp and ignition etc OK
Checked spark at plug - OK bright healthy spark
Removed carb - cleaned all jets OK

Sometimes she will almost start - just fires a few times but will not pick up revs and needs throttle to do this otherwise rarely fires at all - checked fuel level OK, tried easystart but again not really any better - had aircleaner on/off still NG.

Thought I was frustrated before when I couldn't get back light to work but this is worse after it was firing first or second kick - -is there something any you guys can suggest please?

Thanks in advance for your support

[Warkton Tornado No.1]

Lambretta ownership can be very frustrating...

My knee jerk reaction:

You'll still get a spark even if the condenser is failing.

[harps2]

Lambretta ownership can be very frustrating...

My knee jerk reaction:
You'll still get a spark even if the condenser is failing.

Thanks Tornado
I changed the condensor when rebuilding the stator - can it really have gone already? - having said that, something has changed as it started first or second kick for about two weeks and then now its wont start....................

[grandpa]

Make sure choke is working.or remove bellows and hold a piece a cardboard over carb mouthpiece while you kick her over as a makepiece choke
Grandpa

[Wack]

Check the terminal from the condenser to the points is not touching the flywheel.

[MK Monty]

check the woodruff key a spark at the wrong time is no good. they seem to shear dead easy these days, I never did my flywheel up dead tight when setting timing as I knew it would be off again in a minute, lost a few because of it, easy to find the bugger stuck on the magnate

[harps2]

check the woodruff key a spark at the wrong time is no good. they seem to shear dead easy these days, I never did my flywheel up dead tight when setting timing as I knew it would be off again in a minute, lost a few because of it, easy to find the bugger stuck on the magnate

Checked - removed flywheel - rechecked timing and re-tightened - I did as you said on previous LI 125 and woodruff key sheared now I always torque nut down ha ha but thanks

[harps2]

Check the terminal from the condenser to the points is not touching the flywheel.

Checked - removed flywheel - rechecked timing and re-tightened - checked all wires out of way as you suggested - thanks

[harps2]

Make sure choke is working.or remove bellows and hold a piece a cardboard over carb mouthpiece while you kick her over as a makepiece choke
Grandpa

Choke removed - re-routed cable and checked operation - all OK - removed all jets, cleaned - OK checked float operation - OK

[harps2]

TODAYS UPDATE

Managed to get started today after various checks as suggested in previous responses - thanks - not sure exactly what it was but not complaining at the moment - back to REAR LIGHT PROBLEM

Assembled headlight with all wiring in correct colour coded positions - turned ign key to 2nd position and rear light came on, then turned to 3rd position and rear light got brighter and headlamp also on (H/L OK) but it was only the one filament coming on in either ign position!
Position 3 on ign is bright (Brake light) position 2 on ign is dim light but now I have no brake light from brake pedal - confused now are we ????

Going to go back into headlamp and double check - oh what fun it is restoring a lambretta..................as always any comments or ideas are welcome

[Wack]

To rule it out unplug all the lighting wires from the ign switch and use a piece of wire from the loom brown to touch all the other terminals in turn ie to yellow on hlight bulb holder for pilot, then to black for rear light and the dip and high blue and red. If everything lights up then the switch must be faulty. Also if you're still on the original stator then presumably you're still using the junction box so check that out for continuity and connections.

[harps2]

To rule it out unplug all the lighting wires from the ign switch and use a piece of wire from the loom brown to touch all the other terminals in turn ie to yellow on hlight bulb holder for pilot, then to black for rear light and the dip and high blue and red. If everything lights up then the switch must be faulty. Also if you're still on the original stator then presumably you're still using the junction box so check that out for continuity and connections.

Hi Wack - sorry I forgot to mention its a new ignition switch from scootopia so hopefully OK but will check all the wires in junction box for completeness --

Do you know if I can connect a 6V battery charger to the loom to check all connections etc without the noise/vibration of the scooter with engine running? - if Yes can you confirm where I should attache positive and negative connections - thanks - it would be a lot easier without engine running!

[Wack]

I've not tried a battery charger but should be ok on low amps? You would need to disconnect the loom wires from the junction box and connect them all bar the green to the charger positive then the negative to the frame

[harps2]

Hi ALL
Can anybody else confirm if its OK to attached a 6V battery charger to Harness loom to check wiring/lighting rather than start engine each time?

[Toddy]

Hi ALL
Can anybody else confirm if its OK to attached a 6V battery charger to Harness loom to check wiring/lighting rather than start engine each time?

I always do it that way to check my system live to Brown feed out loom and well earthed

[MK Monty]

Where are you based. I'm sure someone could pop round and have a look for you.

[harps2]

Where are you based. I'm sure someone could pop round and have a look for you.

SEAHAM SR7 8DF North East England

[harps2]

Hi ALL
Can anybody else confirm if its OK to attached a 6V battery charger to Harness loom to check wiring/lighting rather than start engine each time?

I always do it that way to check my system live to Brown feed out loom and well earthed

Hi Toddy

So join live to brown main loom at Junction box or headlamp? - my scooter is li 150 sPECIAL 6V Ac NON BATTERY ??

[MK Monty]

Need a passport for up that far.
Disconnect the brown coming from the regulator going forward. Then connect the battery or charger. The brown is the main feed forward so testing everything after the regulator. Be careful not to short anything.