82 WR430 Husky-Lighting coil?

[Dewy123]

Hi,
I'm just setting up our WR430 for club rego and have got it all wired up but there just isn't enough power to run lights plus horn and so on. There's a second yellow power wire coming from the lighting coil which I guess doubles the amount of watts? Is there any draw back in connecting this second wire? Over heating the lighting coil? Or am I better off running a small 12V battery to boost the reserve power? As the lights work ok for an old bike but I can't get the horn to work unless its revving pretty hard which being a big bore two stoke you then can't hear the horn over engine noise. LOL.
Thanks, Dewy.

[Montynut]

On Motoplat systems that second wire suppllies the horn and tail/stop light while the 'normal' lighting coil is for the headlight. Basically two lighting coils with a common earth. You can not parrallel the lighting coils (ie connect the two supplies together because they are actually AC supplies and out of phase because of the different mounting position of the coil within the flywheel.

Naturally the output of the lighting system is that small that at idle you can not even see the lights working or hear the horn You have to rev the engine quite high to get the system to work and even then you need a torch to see if the headlight is on

You can not run a battery at the same time as using the lighting coils without designing a rectifier system and regulator otherwise you wil fry something. The battery is pure DC while the lighting coil output is very crude AC.

If it is a Motoplat you just have to learn to live with it and eat plenty of carrots

Not sure about other systems but believe Femsa and SEM are similiar.

[Dewy123]

On Motoplat systems that second wire suppllies the horn and tail/stop light while the 'normal' lighting coil is for the headlight. Basically two lighting coils with a common earth. You can not parrallel the lighting coils (ie connect the two supplies together because they are actually AC supplies and out of phase because of the different mounting position of the coil within the flywheel.

Naturally the output of the lighting system is that small that at idle you can not even see the lights working or hear the horn You have to rev the engine quite high to get the system to work and even then you need a torch to see if the headlight is on

You can not run a battery at the same time as using the lighting coils without designing a rectifier system and regulator otherwise you wil fry something. The battery is pure DC while the lighting coil output is very crude AC.

If it is a Motoplat you just have to learn to live with it and eat plenty of carrots

Not sure about other systems but believe Femsa and SEM are similiar.

Thats not a problem separating the tail/horn wiring from the head light, but do you then need a second ballast resistor to stop over charge/blowing globes? Thanks for the info Montynut. Cheers, Dewy

[Montynut]

Ballast resistor . Was that part of the original wiring as most of the basic no battery/magneto systems do not have the capacity or need for a ballast resistor. Usually there is only a ballast resistor when there is a rectifier/regulator installed to reduce the work required by the regulator there is also usually a largish capacitor to act as a 'storage' type load to help the regulator. The ballast resistor is then only in circuit when the headlight is off so that the regulator has a load to supply and therefore makes it's job easier.

In a AC magneto systems there could possibly be a case for a VDR (voltage dependent resister) which would limit high voltage and would normally be in the tail/stop light circuit to stop globes blowing.

If there is a ballast resister in the headlight circuit then it should only be in circuit when the headlight is off otherwise it will drop the voltage that much the headlight probably will not glow.

[Dewy123]

Sorry probably got my terminology wrong  I'm pretty sure its a capacitor? Square block with one wire going into it? Anyway, I've set it up with the second wire running the horn only as i can't see a problem with it being connected to the horn when majority of the time its doing nothing. Thanks Dewy.

[Maicoman]

A block with a single wire sounds like the rectifier or regulator. I know the one you mean, basically the same system on Huskies, Maico's anything with Motoplat set up. The spare power wire on the Huskies was designed to run a Safari light. I have that on my 85 WR and my 82 XC also has a lighting coil even though it wasn't designed to run lights. On my WR I put a multimeter on that wire and it was unregulated AC volts. It was a pretty high reading. I wouldn't connect it up otherwise you are bound to blow the lights when you rev it.

Check out this link to Cafe Husky they have alot of PDF Technical bulletins that may help:
http://www.cafehusky.com/threads/vintage-husqvarna-service-bulletins.1312/

[grouty]

Dewy .... I had exactly the same problem with my 78 390WR. There simply was not enough power to run the stuff we need in the UK for an "MOT".
My solution (and it works well), is to wire the headlamp dip and main beam into the 35w wire. I run the stop and tail from a R/C car nicad pack. This gives me about 14 volts. I use a 12 volt LED bulb in the rear. Very bright and does not fade with the revs dropping (ideal on the road). I tested the nicad pack to see how long it would last. I got bored after leaving in on continiously for a month ! You will need to fit a voltage regulator in the main system to stop it blowing the 6v bulbs. They are cheap, small and fit neatly beside the Motoplat coil under the tank.
The other feed from the alternator is now redundant on mine as there is not enough power to run a 6v AC horn. These take much more power than a DC unit. I have now fitted a 12v DC horn and connected it to the Nicad pack.
The nicad pack sits neatly on top of the air box on the 78. It does not need to come out again as I just plug it into a charger for a few hours. When I use the bike I plug the feed to the lights into it using a Tamiya battery connector. (small and idiot proof !).
If you need pictures, just shout and I'll see what I can do.