Scooterotica

if theres one thing id love to be able to do, is diagnose and rule out electrical problems.
However, its something alien to me.
iv a multimeter, but it has so many dials and numbers on it.
Is there a good website or a simple way to learn about scooter wiring?
Surely some of the experts on here could furnish us with some tips, readings and general help?

Really you need to forget scooter wiring and go back to basics.
You need to understand voltage, resistance, current, and power.
A multimeter is a wonderfully simple tool. First grasp an understanding of voltage and how to measure it in either AC or DC. Most magnetos output AC and can show anything from 12 volts to 16 volts.
Best use of the meter would be for measuring continuity, known as resistance and measured in ohms (yhe omega sign).
Perfect circuit is zero ohms.

Hard to fault find on any auto application without a grasp of the basics.

well, thats a start chris, cheers for that,

Chris is right, you need to get to grips with some basic theory, have a look at this, it goes on to talk about house electrics but the parallel with water flow used to explain is very useful http://kevinboone.net/electricity.html

Get yourself a 9 volt pp9.battery a fuse or a lightbulb.
Your meter will have 2 leads black (negative or ground) and red (positive or live). The meter will have a dial that you can select what you want to measure. AC it may have a wiggly line~. Choose DC. It may show----. Put the black probe on your - on the battery and the red on the +. Your meter should tell you what voltage is measured it should be 9.00 volts dc. 5 or 6 would tell you the battery is nearly flat. 9 would tell you its new and good to go.
Set your meter to ohms or omega sign. Not available on my phone looks like a horse shoe. It.may have a 2nd setting with a beep. Touch the black and red probes together and you will get a reading or a beep. The beep inicates there is continuity between the 2 probes. If you have a fuse or a light bulb and you want to know is it good you can put the probe on either end of the fuse or the contacts and it will beep . No beep duff bulb. You can do the same between the ends of a wire say the brown at the stator end and the brown in the headset. No beep tells you if the wire has a break.
Set it to ~ put one probe on the contact on your running headlight bulb and the other to a good earth point on the headset and you can measure the AC volts to the headlight. It may be low at 8 or 9 volts on tickover but rise to 12 ish with a few revs.if it goes to 15-18 its a good indicator that your regulator is not working and you may be blowing bulbs. None of the above will kill you if you get it wrong but dont practice on the house mains

monty, thank you, i very much appreciate that, its something i wish to learn, to help myself, and others, as electrics on lammies can be a pain, cheers

You will find a lot of Lambretta electrical faults are simply down to poor worn out bullet connectors that either fail to make any contact or make a very high resistance contact.
Secondly earth connections which are all important corrode and cause so many problems with lighting circuits. A good set of crimpers and new connectors are essential.
Lastly take a photograph of any wiring before you disconnect and only disconnect 1 wire at a time.

Just a word of warning re crimp on Terminals
The Blue plastic coated type that you use pliers to crimp on are crap in my opinion. The amount of faults I find when the crimp has not been secured enough or worse still cut the wire and it falls off within weeks. I do use these crimps but I remove the plastic cover, solder it and heat shrink the end. Blue Bullets for instance are too fat for a Lambretta connector but if you look at it carefully it has a join I nip up one half of the terminal into itself then squeeze the other half on top. It makes the bullet triangle shaped with 3 good contact surfaces and they don't fall out. I know others sell the dogs doodahs kits of connectors but these are readily available.

I was going to mention the solder but thought it might start getting complicated. In hindsight, I didn't give the best advice because that is exactly the problem I have experienced and I do exactly as you do. Solder it and I bought a packet of multi coloured and multi sized heat shrink so I can replicate the colour.

Good topic with great responses!

What size heartstrings would be best to use?