Help needed with 4G distributor drive

[Richard Kal]

Hi all,
I am building a 1938 4G the hard way; started with just a frame!

I have been able to find many of the parts for the magneto / dynamo assembly, but need advice please, as I have started with nothing for reference.

I would love more technical info on the magneto; I have downloaded the exploded diagram from the Draganfly web-site, but I am discovering this doesn't show all the parts.

I have a magneto body and armature, and a 6V Thorpsark electronic ignition on the way.

Jorgen has been a great help; supplied a dynamo and the pair of drive gears (fibre and steel).

I have tracked down two distributor drive (end) plates 464266. Both have been repaired, but are serviceable. Was it common for them to break apart? What caused this to happen?

I also have scored a pair of bevel drive shafts; good condition.

Some of the other things I need help with are:
(a) 464261 Grease dashpot: Does anyone have one they would part with? Alternatively, if someone could sketch one, with dimensions and maybe a pic of it disassembled, I will be able to make a new one (and another for the helpful person).
(b) Fibre washers under bevel drive shafts: Nicholson's Motorcycle Mechanics explain that there is a fibre washer under each of the bevel drive shafts; can someone please confirm the dimensions of the washer(s)?
(c) 463665 Washer; between Armature nut, and drive gear
(d) 463638 Gasket (or shim?) between end plate 464266, and the magneto body
(e) 400316 Distributor cap (& screw)
(f) 1 x spring clip for the distributor cap

Also, is there a gasket between the distributor cap, and the face of the end plate?

Many thanks,

Richard

[brenton.roy]

Hi Richard,
Hopefully you'll get the answers you are looking for.
If not, I have a '46 4G in bits and can have a look at how the maggy and distributor are assembled. Unfortunately, no spares.
I'm pretty impressed with your starting point!!! You are definitely braver than me.
I don't know what else you need, but there was a heap of Mk1 stuff on eBay recently that didn't seem to be selling quickly. Maybe the seller would be open to offers?
Brenton

[paul_turner]

Hi Richard
Can I suggest you speak to Merv Kendall ( he advertises in the back of Cheval ) and is an authority on such matters and I'm pretty sure our Square four spares man Bruce Longman has the distributor clips
Good luck
Paul T

[Richard Kal]

Hi Paul,
Thanks for the advice! I will email Merv.

I sent Bruce a letter 3 months ago, re square four parts, but haven't had a response. Does he have an email address?

Thanks,

Richard

[chris.shearwood]

Hello Richard,
The 400316A Clips are in stock at Draganfly as is the 400316B Screw although when you order the cap the screw is usually included. I think Draganfly can supply the 400316 Caps but at an expensive price.

As the 463638 Gasket does not appear to be available at Draganfly you could make one out of regular gasket paper i.e. roughly .025" thickness. When you are putting everything together you can verify whether that thickness causes tightness or looseness in the assembly. I think its purpose is just to keep the grease in and the elements out.

I can't say for sure the thickness of the fibre washers located at the blind ends of the worm gears but I would suggest washers that fit snugly in the holes with a thickness of about .040". Again, on assembly, you will see if the thickness that you have chosen causes any looseness, tightness or alignment problems. I guess their purpose is to locate the worm gears properly but I wonder if they are absolutely necessary. I can't remember if I put any in my bike or not.

I'll attach a photo of the outside of the Grease Dashpot or Screw Down Greaser. I am hesitant to take it apart. You know the adage: "If it ain't broke, don't f... with it". I am hoping someone else on this Forum will have one sitting on their bench and will be able to take photos for you. Anyway, it's a simple device which Nicholson partially describes. Essentially a hollow tube threaded on both ends with the inner end locating in the groove of the vertical worm gear and the outer end being covered by a hollow, threaded, knobbed cylinder. Inside the knobbed cylinder are a couple of wire springs to ensure it doesn't unscrew easily.

Where are you located? If you live near me, come on over with a case of beer and you'll probably be able to convince me to take it apart to show you.

[Richard Kal]

Hi Chris,
Thanks very much for the pics and info, and the offer to pop over.

However, being from Western Australia, I won't be able to make dinner tonight!

The info is great!

Regards,

Richard

[john.whiting]

What you call a grease dashpot,appears to be a simple screw up greaser,called a Stauffer ,in some circles.These are fitted to many machines,and all you need is one with the correct thread.Regards John.