Starter Solenoid

[Mick Taylor]

I bought a new solenoid for my Classic only to find later on that I didn't need it......however I also have an electric start Mk3 Commando that could use a new solenoid.Both systems seem to run ballast resistors and 6v coils (I think)....but my grasp of electrics is pretty basic to say the least and the Commando has positive earth electrics (WHY?...WTF!) which I still need to get my head round.Does anyone happen to know if the Lucas solenoid intended for the Classic would make a suitable alternative to the Prestolite original on the Commando?Thanks.........Mick.

[gripper]

The Lucas solenoid won't know what is going through it and it doesn't matter. It's just an electrically operated switch. It should be suitable for a Commando. Some Lucas solenoids have a manual button on them which it quite handy, Saves spark eroding your best screwdriver away to nothing when you are practicing your hot-wiring technique

[Mick Taylor]

Thanks for that.....hot wiring? that's way beyond my electrical abilities.I'll compare the contacts and see if I can fit it, at first glance it looks like it should.Mick.

[johnbirchjar]

Hi Mick,"Hot Wiring" the starter motor,(in the old days) was when the selanoid went on the blink,a screwdriver was used to "arc" between the two terminals on the starter motor,thus by-passing the u/s selanoid,I havn't had to do this for many years,not sure if it is still possible with modern vehicles,ride safe,J.B.

[Mick Taylor]

Hi John, actually, I had to do that (bridge the solenoid) with my Classic when I first bought it to get it started......which is why I bought a new solenoid for it; however by the time I'd been through it all, cleaning all the contacts etc it decided to work and still works perfectly, hence the new one is now spare.That said, I class myself as a complete plank with electrical issues generally, I bought my Mk3 Commando part dismantled, I've never seen a battery in it and it has bizarre (to someone brought up on a diet of very logical 1970s Japanese wiring) electrics so I have a bit of learning to do.Ballast resistors.....Zener diodes.....Capacitors......Positive earth!!!?......it's all Greek to me right now.Mick.

[johnbirchjar]

Mick,you are not alone J.B.

[FloridaMike]

Mick,Greek to English translator ;-)Positive ground - the electricity doesn't care which way it flows, observe polarity on zener, rectifier, battery (or capacitor) and coils and you will be fine. You may have to think about it because everything is backwards from what we are used to.Zener - this is the voltage regulator, it shunts excess voltage harmlessly to ground (saves your light bulbs and battery), no adjustment, the nut holding it on is tightened to something like 2.0 ft lbs (that's two point zero, not 20) so be careful not to overtighten it or it will break the stud.Capacitor - used to replace the battery on race bikes. The idea is that when you kick the bike over a few times the capacitor will store enough energy for the ignition to work. In practice, it just improves your vocabulary of profanities. Replace with a battery (12 volts) which fits the space, remember, positive is ground! This was originally for competition, especially off-road, where batteries couldn't take the beating. In a capacitor start system, you take the beating instead. You CANNOT get electric start to work off a capacitor, there has to be a battery. Since you are talking about a solenoid, that means there's an electric starter and you need a conventional battery.The battery replacement capacitor is fairly large and hangs off a spring. If the capacitor on your bike is smaller and mounts with a screw or two, it is a noise suppression capacitor for use on bikes with a radio.These are actually much simpler than Japanese bikes, there's much less to untangle - it is just unfamiliar. Sounds like all the parts may not be there (did you mention the rectifier?) but this isn't rocket science, it wires up just like an old Bonneville, plus the electric start wires.Best Regards,Mike

[gripper]

If you are hot wiring from scratch you will have to supply power to the coil as well to bypass the ignition switch. or just do what they do in the films, rip a handful of wires out from under the steering wheel and touch a few of them together and off you go, (probably in a sheet of flame)

[johnbirchjar]

Ah ha , so it's you who wrote the scripts for "Hot wiring " in films,