A100 rides again..

[A100man]

Hi y'all.

I'm back in the vogue of dicking about with my old A100 which I just got back on the road after about 5 years (pumped tyres up and cleaned carb - started too with some help from carb cleaner on very old fuel )

I have a GP100 spoked wheel disc brake front end (rare) to try and fit and I thought I'd have a go at improving the lighting too.

As far as i recall the headlight is 6V and I think works on half wave rectified volts, or maybe it's full AC direct from a dedicated coil on the alternator and not off the battery

Anyone got advice on fitting a LED lamp? I guess if full AC this not possible.
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Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[Nobby the Bastard]

LED front is doable, you just need a reversed polarity led, rear isn't unless you have a seperate fitting for the brake and rear lights.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[blurredman]

Dunno about the bulb type but I have a P15D bulb on my Suzuki of similar vintage. Was also toying the idea of maybe buying 25w halogen bulb instead of the 18w or 25w incandescent currently inside. Could be an idea if you don't want to mess with the wiring ?
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CBT: 12/06/10, Theory: 22/09/10, Module 1: 09/11/10, Module 2: 19/01/11
Past: 1991 Honda CG125BR-J, 1992 (1980) Honda XL125S, 1996 Kawasaki GPZ500S.
Current: 1973 MZ ES250/2 - 17k. , 1979 Suzuki TS185ER - 9k, 1981 Honda CX500B - 91k, 1987 MZ ETZ250 (295cc) - 38k, 1989 MZ ETZ251 - 49k

[A100man]

P15D looks likely I guess I just need to check the fitting and google whats out there..

.. even halogen would be an improvement if you can get them.
____________________
Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[redeem ouzzer]

I'd love another A100, by far the best bike i've ever owned. I wouldn't modify it though - it would be 100% original as Suzuki intended it.
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Be a REAL MAN!

[A100man]

[stinkwheel]

If it's properly half rectified, you can use an LED, you'll need to check if it's positive or negative earth (put a meter on it with the common lead to the frame and see if it reads a + or - reading, a + reading means it's negative earth). If it's fullwave AC, they don't work (I tried, it went bang).

Still options though. One would be to halfwave rectify it with a diode in the headlight feed then use the appropriate polarity LED bulb (or buy one and see if it works and if it doesn't, fit the diode the other way round).

The other would be to convert it to DC lighting off the battery which at its simplest with most bikes of that era fitted with a split charging coil would simply be to disconnect the lighting feed from the coil and attach it to the battery instead. To add a very slight layer of complexity, if it's just sending the coil output straight to the battery through a 2-pole selenium rectifier which many of them do, it would also be worth upgrading to a single phase reg/rec which will significantly smooth the output and increase battery life. This is what I did with Mrs stinkwheels YB100.

If it has a ballast resistor, you can safely disconnect it if you fitted a reg/rec.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[MCN]

LEDs will illuminate with lower power than their board is made for. It means they can overheat and die.

The boards accommodate a lot of fuzzy quality.

Wire build glow yellow if not enough oomph. LEDs will light as bright as normal. But their card will be working overtime to let the light work.

Just sayin.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[stinkwheel]

Operating range for the last set of LED headlights I fitted was 3-48v.

DC conversion is probably your best bet. It's what I did on my Enfield Bullet. It has a single phase, 10A alternator charging the smallest battery I could find and is running a thoroughly modern feeling H4 equivalent LED headlamp bulb with which I have navigated forestry tracks in the dark and LED bulbs throughout. The entire electrical system, with engine running, full beam headlight, tail light, flashers and brake lights all on is drawing 4A.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[WD Forte]

LEDs are very possible on old full or half wave AC systems
I stuck em on that old Moby I sometimes work on for guy I know.
In fact, despite the pissy wee stator the Moby had, going for a full 12v DC conversion with leds was quite doable even though it had no battery.
I did put a capacitor on though which gave more consistent light output
but a battery will do a better job.

This also allowed the use of cheap easy to find components should any fail in future
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bikers smell of wee

[A100man]

Full AC direct off the alternator is confirmed. Current blub is 35/35W of this type..

https://www.ebay.co.uk/itm/142832965946

instead of 25/25 ..
____________________
Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[A100man]

[Pete.]

[WD Forte]

[stinkwheel]

[A100man]

[stinkwheel]

[A100man]

Wiring diagram attached,

If I made (or used the now redundant one off the GT250 ) 4 diode bridge rectifier
would I common the load -ve and the alternator 'earth'. The diagram seems to imply the coil output is single ended rather than 'floating'.

Cheers
____________________
Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[stinkwheel]

[A100man]

[WD Forte]

Nope, I made the same mistake wondering where the ignition power came from until I spotted the wee twisty igntion power coil
in the diagram near the points


I think the simplest (and reversible ) option is to keep the windings for the ignition power and the output from the existing coils
( W/R & Y/W)
into a 4 wire 2 phase RegRec with 12v output and battery
the Y/W for lights can be fed via fuse from the ignition switch
There's also resistor I presume is to act as a ad hoc ballast that can be by passed now you'll have a regulator.
12V LED blubs of course and 12v flasher unit

If you want, when I have time I'll frig that diagram with the changes involved, it isn't that much or hard

4 WIRE REGREC ( I used this on that Mobylette)
https://www.ebay.co.uk/itm/123754926003?
https://i.ebayimg.com/images/g/NOAAAOSw5llkSGVm/s-l1600.jpg
____________________
bikers smell of wee

[Nobby the Bastard]

Looks to be a full wave rectifier of a single coil rather than the usual 3 coils halfwave rectified.

(4 diodes in a diamond configeration)
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[A100man]

Hmm, before I get too ahead of myself I need to find a better (brighter)
lamp of the correct fitting.

The one in it looks like this odd bugger.. with the three lugs.

https://i.ebayimg.com/images/g/a7wAAOSwkydkiWhr/s-l400.jpg
____________________
Now: A100, GT250A, XJ598, FZ750

Then: Fizz, RS200, KL250, XJ550, Laverda Alpina, XJ600, FZS600

[Nobby the Bastard]

Edd China actually did a demonstration on Wheeler Dealers of bulbs of different cost of the same fitting type and wattage. There higher quality bulbs out there which are brighter and provide a better beam pattern.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[A100man]