Magdyno testing & refurb - any suggestions where? B31 1954

[Fraz]

My B31 is intermittently cutting out and doesn't like re-starting.
It's very random and sometimes it runs OK.

I'm now in search of someone who can test my magneto / dynamo and refurb it if needed.

I'm based in Sheffield so local would be great but anywhere recommended would be great.
Thanks

[DAVE BRADY]

Hi,

Try Priory Magnetos.  Not very local but has a good reputation.

Dave.

[KernowPete]

Do you know about Thorspark electronic conversions for magnetos? -
https://www.sussexmotorcycles.com/thorspark.htm
They're relatively cheap and easy to fit. It keeps the manual advance/retard etc as it fits inside the existing magneto. My B31 has one fitted and it works a treat. Might be worth considering?

[yellow B31]

I had my B31 mag. overhauled by Priory Magnetos. Excellent service and a satisfied customer.

[cdsdorset2]

APl magnetoes Shaftesbury.

[Fraz]

Do you know about Thorspark electronic conversions for magnetos? -
https://www.sussexmotorcycles.com/thorspark.htm
They're relatively cheap and easy to fit. It keeps the manual advance/retard etc as it fits inside the existing magneto. My B31 has one fitted and it works a treat. Might be worth considering?

Just looked at the link (thank you)
Did you convert yours to 12v? And would it be a big job to convert?

Do you know which model of theirs, is fitted to yours?
Many thanks

[KernowPete]

Mine is 6v. It was fitted by a previous owner. Never confirmed if it is actually a thorspark but it's basically the same as I understand it

[KernowPete]

Here's a 6v one. Probably correct but you need to check it out -
https://www.sussexmotorcycles.com/thorsparksecureonlineshop/prod_955371-Lucas-MO1-Magdyno-bike-with-6-volt-electrics.html
Mine has a coil fitted under the top frame tube and the power connections run back to the battery with a switch and inline fuse holder. I believe you need a timing light to set it up but if you're happy with doing a bit of wiring it should be straight forwards.

[KernowPete]

Just reading some of the thorspark reviews and someone mentioned that sometimes their bike fires just from turning the ignition on. I've had the same thing on mine and something to be aware of is it might be more likely to kick back whilst turning over slowly to get past TDC. It's happened to me a couple of times before I learnt to leave the ignition off until I give it starting kick. The kick backs were very soft though so not too serious 

[KernowPete]

I'm actually in the middle of rewiring my battery and ignition supply as it was badly grafted in to the original wiring resulting in a misfire when the lights were on. This was just down to poor connections. If you decide to go for one of these I'll happily send pictures of what I've done etc.

[Derek996]

...And would it be a big job to convert?

I run my B32 at 12V. When I bought it had an E3HM 36W dynamo fitted which didn't work anyway and needed a rebuild but I managed to obtain a non-working E3LM which is a 60W model. I then rebuilt this with a new 12V armature and 12V field winding and of course new bearings and brushes. I fitted a DVR2 regulator into the old Voltage Control Unit and a 12V battery inside the existing Exide shell. Not cheap, probably cost the best part of £200 altogether but has the convenience of bulbs being easily obtained and less current through the wires, although I'm running LEDs throughout now.

[neil1964]

I do like the look of the Thorspark system (esp if it keeps the manual advance and retard but as Derek points out above you have to have an A1 dynamo and battery for longer runs - short runs it uses little juice so you could go total loss - at a push!

[Bigsingle]

Have you cleaned the slip ring and made sure the HT carbon isn't stuck .

[V500]

To the OP, before throwing money at it I'd suggest going back to basics and giving the bike a good check over. As the old saying goes, 80% of mag faults are down to the carb, etc etc.
That said, have you checked the spark when the bike is reluctant to start?

[KernowPete]

By the way this is mine -
https://youtu.be/ufXTNDL0ANs?si=qAF1onWPa7-qh4qH
Fell in love with the slow tick over 
If anyone knows this bike I'd love to hear from you!