Yet another white wire question

I don't know. The 6 volts should be fine, it's the 20 watts that concerns me. It seems that would rob the engines spark power and result in lower performance. I could be wrong, we need a professional to help. ALSO, check out spooky tooth lights, I don't think any run off of the wire though. One has a regulated generator to stop the lightbulb blows and the other doesn't. Read through all of them because spooky has more info and seems more reliable than that site cause that other site doesn't have much info.

No it will kill the engine.

lol Shark... whadda tryin' to hint at I wonder

http://motorbicycling.com/f23/lights-run-off-white-wire-no-7306.html

Shark,that light wont work,I bought one like it for 30 bucks ,and it would just kill the engine,I've gave up on the hole head light to white wire thing.I just use battery powered ones now."I'm such a quitter" Randy

Sharksfan said:

Can any one tell me if I could use this head light and run it off of the white wire? I really need a good lighting solution because some of my commute is pretty dark and I am tired of the standard bike light fail rate.



Cev Sealed Beam headlight black 6 volt 20 Watt [CEV-2139b] - $24.99 : Zen Cart!, The Art of E-commerce

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You said that only some of your commute requires the 20w headlight. Run the light off a 6v SLA battery. Then run the white wire through a single diode to keep the battery trickle charged. Because of your large headlight, you will only be able to run it about 10 or 15% of the time without depleting the battery. Choose the battery accordingly. Each amp-hour will give you about 15 minutes of continuous headlight run time. Besides acting as a rectifier, the diode will prevent the connection from killing the spark output.

I use a complete setup (brake light, headlight, tail light, turn signals, horn) that includes a much smaller headlight that I use occasionally. The 1.3ah sla battery has stayed charged after 7 months and 1000 miles.

The engine kits coming out lately seem to have the magneto coil wound with either the wrong size wire or not enough wire on the winding. The ohms reading may be good but if its wound with 28 gauge wire instead of 26 gauge wire they will not idle very well if at all.

Same with the magnet rotor they do not have as much magnet strength even with a known good magnet coil if the rotor is weak the darn light will kill the engine when at lower rpm.

So there is a double trouble with trying to use the white wire if you get an engine with one or the other problem. The last 2 engine I bought are crumby I've changed coils rewound coils, change out rotors until I could get them to work.

I've been checking out getting a magnet charger not having a lot of luck. I found one at an engine shop but even though they don't use it they will not sell it. I'm hoping I can get them to try recharging one of the weak magnet rotors to see if that will help with getting the light to work correctly like on the older bikes I have.

I know a guy here in Texas who might try to charge one for me so I'll have to mail him one or talk to the shop here that has one and not using it anymore. They don't have it wired up any more so it will need some work to get it going.

I've also looked into building a magnet charger the wire price is gulp around $200.00. A factory made charger is over $600.00
Most shops that recharge magnets charge $50.00 I should add that includes the magneto rebuild so just a magnet recharge should be considerably less.. I still don't know if it can be done to these magnet rotors.

If you want to try a light bulb just to see if your system will work with a light find a 3 to 6 volt bulb for a flashlight if it lights the bulb and doesn't kill the engine then you have one of the better magnet coils and magnet rotors. The bulb will work for a while but they soon burn out.
Do check your bike magneto white wire out put with the simple bulb test before you decide to buy a light from me it can save you and me some headaches. I hope the rewinding and a recharge of the rotor will make any china engines ignition system work for running lights.

Randog707 said:

Shark,that light wont work,I bought one like it for 30 bucks ,and it would just kill the engine,I've gave up on the hole head light to white wire thing.I just use battery powered ones now."I'm such a quitter" Randy

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Mine works great and have mounted it on many different bikes.

http://s390.photobucket.com/albums/oo347/FR31MB/Light/

Normans Light videos pictures by FR31MB - Photobucket

I used one of these for my front headlight:

1 WATT WHITE ULTRA-ULTRA BRIGHT LED | AllElectronics.com

and one of these for the rear light:

CHROME 4 LED DISPLAY, RED | AllElectronics.com

If you want to get real fancy you can put a rectifier in and convert the AC current coming from the white wire to DC current. I intended to do this to eliminate the flickering, however the engine rpms are so high the flicker is so fast you cant even tell its flickering unless you are idling.

I'll post a diagram when Im on my computer with photoshop. Yes, both lights run off of the white wire, I have the front LED mounted in a retro bullet headlight. It works great, it will light up the road in front of you. Its similar to the LED they use in maglites.

Here ya go, I'll try and take some pictures of my actual setup tomorrow.

My setup is a little different so someone correct me if I forgot to put something in the diagram. I use the white wire to go to a kill switch and then to the lights, and I ground it on the frame, but this is simpler:

Short answer - no, the white wire will not work with a 20 Watt light. The magneto was designed to only make several Watts of power at 6 volts +/- of AC current, which is enough to run the engine and a low-power (3 Watts max) head & tail light system. You can run low-power LED lighting systems off the white wire, but the light output is relatively low and/or focused into a tight beam. You can run a 20 Watt incandescent lamp (like your photo) if you run it off a battery. You can trickle charge the battery from the white wire. Since the magneto makes alternating current, you will need at least one diode to rectify the current, but a full-wave bridge rectifier (basically 4 diodes) would be better. If you want to charge the battery properly, you should have a voltage regulator as well, but the extra cost may not be worth the trouble - try a single diode or a full-wave bridge rectifier (both available from RadioShack) with a small 6 volt lead-acid battery and see how well the simple system works for you. Otherwise, you can make a 6 or 12 volt electrical system (12 volt automotive components are more readily available and less expensive) that is independent of the white wire and charge it with a wall wart. For my electrical system, I'm going independent of the white wire using two 10-cell, AA nickle-metal hydride battery packs (2 Amp-Hour, 12 volts each where one battery is a backup); a 20 Watt, 12 volt landscape flood light (in a homemade housing); and LED tail light and turn signals based on automotive components. If I do find myself out at night and both battery packs are exhausted, I can stop anywhere and buy 10 AA alkaline batteries and put them into the battery holder to get me home. My main reason for wanting lights is to be seen, but I also want to see the road ahead. I don't plan to commute at night. If I did, I use a 7 AH, 12v SLA gel-cell battery.

Earthman said:

Short answer - no, the white wire will not work with a 20 Watt light. The magneto was designed to only make several Watts of power at 6 volts +/- of AC current, which is enough to run the engine and a low-power (3 Watts max) head & tail light system. You can run low-power LED lighting systems off the white wire, but the light output is relatively low and/or focused into a tight beam. You can run a 20 Watt incandescent lamp (like your photo) if you run it off a battery. You can trickle charge the battery from the white wire. Since the magneto makes alternating current, you will need at least one diode to rectify the current, but a full-wave bridge rectifier (basically 4 diodes) would be better. If you want to charge the battery properly, you should have a voltage regulator as well, but the extra cost may not be worth the trouble - try a single diode or a full-wave bridge rectifier (both available from RadioShack) with a small 6 volt lead-acid battery and see how well the simple system works for you....

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All good info but I would like to add the following:

Even though it is possible to get more charging power with a full wave bridge, there are problems. A full wave uses both half cycles to charge the battery, including the half cycle that generates the spark. Draw too much power and you kill the engine. The single diode half-wave rectifier will not kill the spark since it can be setup to draw power from the unused half cycle. Also, if you use a bridge, you cannot use a chassis ground. All of your components will have to be electrically isolated from ground. All of my components ground to the frame and use a single power wire.

I have found that you do not need a regulator when using a single diode and an 6v SLA battery. I have run it with and without a regulator. The battery never overcharges or gases.

The white wire can charge your battery. But if you have large lights and run them often enough, you may still need an auxiliary charger. The white wire charger works best with LED lights and maybe occasional use of a larger incandescent headlight.

I'm sure yours are all good and valid points, Scotchmo. The single diode will have less of a voltage drop as well. Thanks for the info.

All good info. I found it doesn't take a lot to kill the engine especially when idling up to a stop light. An option to consider: on the web and ebay there are 6v 2.5w halogen bulbs available from the UK. They are not magic, nor put out like 20w, but they are a lot brighter for the watts than a regular flashlight bulb, and you can use them in traditional headlight assemblies that focus better than most LEDs. I spent a lot of time messing with different ideas, chargers, etc, and finally settled on dual headlights. One is a 70LED on AA bats, and one is a halogen bulb off the white wire. I never hit on a single light that was dependable enough so now I have redundancy. An extra set of AAs charging at home, and swap out every few days.

I agree, if someone invent a really bright dependable self-contained light system that would be powered by the white wire, well, they'd have some sales!