Forum

[colinp]

Hi,

My 1956 500 twin has a Lucas Dynamo on it. The end of dynamo emerges just above the cover for the timing chains. It is threaded and I can feel it rotates when the engine is running. Should this have anything on it? I have seen nuts for the Lucas E3L dynamo - does my bike need something like that. I am concerned that it may hold the dynamo in place as well as the strap? Thanks in advance.

[Adrian]

If you haven't already seen this, the online parts book might help you identify any missing parts. A.



http://www.hitchcocksmotorcycles.com/pa ... 500cc_Twin_

[Mark M]

Colin, what you need (if I have understood your question properly) is a special nut like this: Ebay item number320912088143. Our Hosts don't stock them so I feel justified in posting this! I recently had to buy one for my 1955 Bullet (the Ebay Bullet!)

REgards, Mark

[colinp]

Thank you both for your replies. As ever I had checked Hitchcocks Parts Online (I spend a LOT of time looking at the exploded diagrams and have bought a copy of the parts book).

Mark M thank you once again - I must now admit that I have bought one of those nuts having seen some images of the dynamo on the web. What I still don't quite get is that the nut goes onto a thread that rotates. I take it you don't tighten it up all the way or else it could inhibit the dynamo turning? Being thick what does the nut do? Does it loosely hold the dynamo in place? Thanks again.

[Mark M]

It doesn't rotate. I can't explain why yours is!

REgards, Mark

[colinp]

Oooooooo - that's a bit worrying perhaps I need to take the dynamo off and take a closer look. Thanks for the fast reply Mark M.

[colinp]

FYI I fitted the nut (not too tightly) and it is not rotating. My best guess is that the thread is from a mounting bolt inside the dynamo that was being turned by other moving parts?

[Mark M]

Looks like it! The purpose of that stud is to locate the dynamo endways into the magneto body so it shouldn't rotate. Hopefully now it has an end load on it it won't move again.

REgards, Mark