'79 TS185 battery bypass
 

One of the things that I like best about this bike is that it doesn't need a battery to start / run.
The problem is that the headlight will burn out if the bike is ridden without a battery. Apparently, the magneto puts out too much voltage without the battery load.

This magneto has several outputs:
yellow\red wire = lights
yellow\white wire = charge battery
green wire (tap of charge coil) = unused

Is there a fix to re-wire the lights to a different magneto output so a batteryless bike can be ridden without burning out the headlight?

If I wire the lights to the charge coil, will the coil be able to handle the extra load without burning out?

I noticed that newer models of this bike have a voltage regulator connected to the lights. Should I put one of these on my bike?

Anybody tried this b4?
Thanks!

hi,
im not a pro but I think most two strokes bike can strart with no bat. depending on the wiring of course.... my rc80 & gp100 also runs well without the bat but the light are like what you said. I've had a GP100 that never used bat but had a something fitted to the wiring to make it not too bright untill the light bursn out! But the problem is I dont know whats its called. My RC80 also runs without a battery but my lights never burnt out coz it was never bright.... I ride in the cities with these bikes I dont really need the lights, its more for others to see me & also for street rules purposes only. I'll find out what its called and get back to you.

What you what is a battery eliminator.
From a Kawasaki triples website:

Replace it with a 50,000-mfd, 16VDC computer grade capacitor.



What to do:

1. Remove battery.
2. Wrap capacitor in ¼” to ½” foam sponge rubber extending over each end of capacitor and tape it so it will not come off. The foam should be thick enough so the capacitor is a snug fit in the battery box.
3. Connect the black lead (-) to a clean tight ground. Remove paint and use serrated washer under ground lead bolt.
4. Connect the red lead (+) as the battery hot lead was connected.



Installation test:

1. Turn lights off.
2. Start bike and run for at least one minute.
3. Turn bike off.
4. Turn ignition on, neutral lamp should light for 5 to 15 seconds. (Capacitor should hold this charge for days)



System check with bike running:

1. Connect voltmeter across ground and capacitor hot lead.
2. At 1500 RPM or above, voltmeter should read 13-15 volts with a steady meter, that is, the reading should not change or bounce around.
3. With the lights on, voltage should be 12 volts or above if RPM is 1500 or above.
4. At 1500 RPM or below, voltage will drop if turn signals or brake light are used.



Note: If voltage readings at 1500 RPM are above 16 volts or below 12 volts, the voltage regulator is probably defective. This also causes short bulb life.



The battery eliminator solves a number of problems:

1. Battery acid leaking on pipes, wheels, etc.
2. Frequent battery replacement due to vibration.
3. Elimination of battery weight.
4. Voltage swings of defective battery resulting in weak spark, CDI failure, light failure, etc.



Disadvantages of battery eliminator are:

1. Lights won’t work if bike is not running.

regards

Nigel in NZ

Is that all?

"Disadvantages of battery eliminator are:

1. Lights won’t work if bike is not running.

regards

Nigel in NZ"

what if the bike uses an electric starter? would it still work? It would be nice if I dont need battery for my 650.

Tampering Results
 

I put in a 40000 microfarad 16V capacitor where the battery was - this got my horn to work (haven't heard that sound in a long time:D). The wiring diagram shows the headlight on a seperate circuit driven by its own coil, so the capacitor did not help the overvoltage on the headlight.
I tried connecting the lights to the battery charge coil (yellow\white wire). The extra load caused the voltage to collapse where the tail light no longer lit and the headlight was a soft yellow at best. The green wire connected to the lights gave a dim orange on the filament.

I ended up connecting the lights back to the original (yellow\red) wire through a rectifier (with heatsink). This should cut the power to the headlight in half.
The light is quite bright. I ran the bike up and down the street and the headlight didn't burn out immediately, so maybe it'll work like this. If the headlight does burn out, I'm going to replace it with a 12V bulb and remove the rectifier...

Has anybody ever heard of a bike with a 6V battery and a 12V headlight?

Thanks for your inspiration!

Opps!
 

Yeah, I knew that the Suzuki had a separate lighting coil, but it must connect to the battery somehow, so I was assuming that it could still work. Damn. I have a friend with about 20 old Yamaha two-strokes, all restored, and he uses a commercial battery eliminator, but the company folded last year. The ones he uses works with the lights properly. I will ask him the name and see if there is anyone making them again.

Osama Radzi, sorry I was not more specific, but this only applies to these old style two-stroke magneto-type ignition bikes, that have kick start.

regards

Nigel in NZ

[quote=Osama Radzi;212671]hi,
im not a pro but I think most two strokes bike can strart with no bat. quote]

thats what I thought.

Thanx for clearing things up Nigel:thumbup1:

my experience of running an old triumph batteryless was the idle with the lights on was rough & very easy to stall. it seemed that at low revs the charging circut couldnt provide enough power to make the bike run properly.

Yes that's true of my Norton too , but the Lucas system on the Brit bikes is an alternator and employs a rectifier/regulator ,whereas I'm assuming the two strokes run a flywheel mag system .
In which case the lights would probably be supplied by a separate coil[s] from the flywheel magneto and run on AC and therefore not affect the ignition at all as the ignition spark would be supplied by a separate coil from the flywheel mag .

Those style magneto's give out a max amount of watts AC so all the bulbs must be present and working including speedo and tacho bulbs and if they are blown it puts more wattage to headlight and tail bulbs. You could try a 12v tail bulb which would starve the head bulb a bit
Dave

you learn something everyday & so on. ive never had a 2smoke so was unaware of that.

My Magneto
 

You're right, Dix - most of the time.
This bike's magneto has 3 coils feeding 3 independant / seperate circuits:
1. Ignition coil - makes the spark that maked the engine go round. Not affected by battery, etc.
2. Battery charge coil - gets rectified to charge battery. Battery feeds horn & brake light.
3. Headlight coil - originally feeds AC (mine now has rectifier) to headlight & dash lights

My dash lights are long gone, but I can't believe that they would make enough load to save the headlight !?? I don't understand how this worked when new? Maybe the turn signal lights - also long gone - gave the load to save the headlight?

The good news is that I've driven my bike a lot by now and the headlight (with rectifier) has not burned out. Last night, I drove it after dark and there was plenty of light to see where I was going, so it looks like I have a permanent fix...
:scooter: