12 volt dynamo systems

[dick.warne]

If you do some long trips at night then you will need 12 volt lights. Upgrades are not cheap, but the first time you turn your H4 headlamp on you will forget about the money! The first thing is to have your dynamo tweaked to 12 volts by your own favourite expert; I have used Sean Hawker and Merv Kendal[AOMCC], and excellent jobs from both. Next up is a solid-state regulator. On my HS I'm using a DYNO-TEC unit bought from Sean Hawker. These units allow you to operate at 6 volts as well, and -ve or +ve earth. Finally all these amps thus generated need a home in a 12 volt battery, and I've had excellent results with both Burlen and Cyclon units. Both these comprise 2 solid-state cells inside a replica hard rubber case. This set-up will balance the full electrical load at 25mph in top gear, and with a 60/55 watt headlamp.
I don't have any experience of ALTON units. Steve Carter is the expert here!

[Steven.Carter]

Me an expert I have fitted two of theses Alton Generators are both fine now although I did have some problems at the beginning. On the mag dyno I had to fit a newer stronger clutch spring and the belt drive that came with the Alton for my Huntmaster got contaminated with oil. It meant that the belt kept slipping so I bought an SRM belt drive kit which has a toothed belt. They do allow the use of a heated jacket for winter riding but you have to fit an isolating switch otherwise the rectifier will flatten the battery.


Steve

[pete.collings]

I have used a JG 12v unit in the past, on both a VH and a FH, and had no problems with either over many years. They just used the dynamo as is without a new 12v fields coil or armature, although the dynamo needed to be in a good working condition (and the magdyno clutch drive grease free!). The instructions with the JG unit say how to rewire the dynamo. Both the above bikes were +ve earth.

The VH balanced a 60w QI headlight above 30mph, the FH was closer to 40mph. I have heard it said that for regular long distance riders they could overcharge the battery, with regular checks on acid level needed. I always used the biggest capacity battery that would sit comfortably on the battey carrier (around 14AH), and found this worked well for the type of riding I did (only the occasional long distance trip).

I have presumed the JG unit is still available, Dave Lindsey used to be the supplier.

[charles.bulloch]

I can recommend a 12V conversion. I use a JG unit which has been 100% reliable. Mind you it did burn out the ancient dynamo fitted to my VH. The rewound unit has been perfect. I use a small battery and run with the lights on permanently.

I tried a 24W QH pilot light as a daytime riding light, which was not satisfactory probably as it got the mount too hot, it slipped out the holder. And a LED stop/tail which bust, but I'm trying with another, these from Paul Goff.

The fibre dynamo drive gear can strip, should this be lubricated?

PS the H4 bulb in my Cibie Z-beam is better than the crystal headlight on my Guzzi V7 Classic.

Charlie

[dick.warne]

Charlie I think most fibre gears on singles get lubricated with the gunge that is always trying to escape from the timing cover, in spite of the breather!

[pete.collings]

Charlie/Dick It is possible to fit an oil seal from a K2F mag to the endplate of a MOI mag (flat head rivets with head inside), you also need to shorten the peg that locates the slipping clutch lockwasher.
You can strip the drive gear for a number of reasons, dynamo sticking/jamming, up and down play in mag bearings, incorrect drive gear on dynamo ( the two types look very similar visually), backfire when starting if slipping clutch does not slip, and doubtless a few more.
With a 12v system you may put a bit more load on the dynamo, so I always tightened the slipping clutch nut as far as possible and removed all oil/grease from the slipping surface, but did lightly grease the fibre teeth. At high revs they can still slip, but should be OK at normal touring speeds (hooligans excepted!)

Since first posting this, I have checked the oil seal type, and it is much larger than a K2F seal as it runs on the (turned down) nut that secures the slipping clutch assembly. Unhelpfully, I don't know what the oil seal was from.......