Thanks, I see. The battery doesn’t need a charge. Just thought I might be running it flat.
Misc: Ignition Electronic Ignition Vs B.T.H Magneto Replacement
- Thread starter Lucas Magneto
- Start date
Looks like it’s a single 12v coil pack I have.
Mounted at the front underside, below the mag cover. Tends to get a bit grubby there though.
I use a BTH magneto on a 1951 Black Shadow with 8:1 compression. Does not give a "big fat spark", but starts easily. I guess a modern EI coil set up like Tri-Spark or Pazon would give a more impressive spark at low rpm as long as the battery is charged. I prefer the magneto as it is quite independent of the other electrics. The Vincent with the BTH has only covered about 3,000 miles so far, but I have used them on Ariel singles over the past 14 years with no troubles.
Just took the bike for a run but it did have trouble starting. The electric start drained the battery and the regulator then compensated. Ammeter showed +4 for a few miles.
Need to read up on the kick technique again.
As well as Rex’s speed shop AO Services (Al Osborne) keeps spares for Rita and will test them.
That is what my Shadow would do after about a hour of riding at night with the headlight on using a RITA. Leaving the house with a fully charged battery, the ammeter would be on zero all day long. As soon as the headlight was on the needle would move into the negative ever so slightly. After a hour the needle was half way across the negative side of the ammeter and the headlight was noticeably dimmer. As soon as the headlight was off the needle would swing half way across the positive side. That was why as soon as the opportunity presented itself to purchase a BTH, I jumped at it.
Haven't ridden at night for a while but I think my Alton/Rita combination puts out just about enough.
Did consider the BTH when I bought the Alton but would have been another £600.
Is starting ok with the BTH?
Just as easy as with the RITA. No problem what so ever. I suspect my experience with the Alton not providing enough power was my headlight, it is a 55/60 watt quartz halogen which uses between 4.5 and 5 amps. Which leaves at most 10 amps for the amplifier and coils. Which I have to admit I have no idea what the consumption was, as after a night ride I would disconnect the battery from the system and connect it to a battery tender so I would have a fully charged battery for the next ride. Determining what the draw of the ignition system actually is, is not that difficult. You only have to place a multimeter between one of the battery terminals and the respective lead to see the current draw when the ignition alone is switched on. This would also confirm what the ammeter says the draw is.