total loss ignition

[bigtoe]

 Hi, I've got a 72 xl 250 and have been racing it for a while but now I think the stator has shit it self so I'm thinking of going total loss system, I purchased the bike already set up for racing, there are four wires all joined together near the coil, one from the stator , one from the coil, one from the points and one from the stop button and that's it, it has the standard coil which  has 6v moulded on it so I suppose thats 6 volt, so I suppose I have to use a 6 volt battrey, so can anyone tell how to wire it up and what size and type battery I need
thanks Greg

[yamaico]

Hey Bigtoe,

Get a small 6v gel cell battery, wire the positive side of the battery to an on/off switch of some sort and then to the positive terminal of the coil. Wire the negative side of the battery to the frame ground. Connect the wire from the points to the negative side of the coil and hook a wire up from your kill switch to this termination point. The other side of the kill switch needs to go to ground. Make sure that you have a good earth between your motor and frame. It is a good idea to have a LED indiction light hooked up on the downstream side of your on/off switch to remind you that the ignition is on. Leaving the power on will not only discharge your battery but it has the potential to burn your coil out if the points are closed.

Hope this helps,

Pete.

[OverTheHill]

without thinking too hard at this stage [sleep time], the old system would be AC ignition so you'll only have a single wire coil under the tank with [being honda] possibly a condenser attached & wired into the only[one] wire leading into the coil. Of course the original wire from the stator coil won't be used any more but the points will be wired to the coil under the tank. Anyway--long story [longer] you'll need a DC 6 volt coil with a condenser hooked in also, any old condenser, nothing special [i think]. talking total loss, there'd be plenty of volts from the lighting coils [if still in there] to charge the battery through a rectifier only without a regulator. Might have to try the lighting wires individually to find enough voltage to charge it without overdoing things & boiling the battery. loosing train of thought but you could run it as a 12 volt system if you wanted [12 volt DC coil], not sure about a charging system but there's usually heaps of volts coming from the lighting coils without bulbs soaking it up. i'm lost now so don't know if [with enough volts] you can charge the battery without a regulator rectifier. British stuff used to run 'zener diodes'--not sure if that's a fancy name for a rectifier someone will put me right [please]. Think the zener used to dump excess voltage to ground so sounds like it regulates at maybe 14 volts or so. Not gonna proof read all that. Cheers.

[bigtoe]

thanks for your help guys, only thing is my coil doesn't have any terminals on it just a condenser attached to it with it's wire disappearing into the coil and only one wire coming out , also I'm getting rid of stator and fly wheel for less weight and so the engine can rev more easily. so does that mean I have to get a new coil with 2 wires or terminals on it and can that be a 12 volt now ? and how many amps should the battery be?

[yamaico]

No problem Bigtoe. Get a 12V coil off any roadbike - Yamaha coils are good because they have a replaceable HT lead - 

http://www.ebay.com.au/itm/Yamaha-RD250-1973-75-12V-High-Performance-Replacement-Ignition-Coil-QC126-/321114281020?pt=UK_Motorcycle_Parts_13&hash=item4ac3e7143c#ht_2252wt_1091

Coils are polarity dependant so check the wiring diagram for the coil that you get. On the Yamaha coil the orange wire is positive.

You can get a battery from Jaycar -

http://www.jaycar.com.au/productView.asp?ID=SB2485

The battery doesn't need to be big as you are only supplying current for the coil.

You will need to either use the condensor that you have or get a new one (any auto parts store) and connect it between the points terminal and ground (the condensor case is the ground connection).

Pete

[yamaico]

Oh yeah, forgot to mention. Grab one of these as well and you can sit it on your seat between races and keep the battery topped up -

http://www.jaycar.com.au/productView.asp?ID=ZM9093