Hi Michael
I am not sure if the petrol tank cap for the T35 and MK V are equal. However I had to make a new one for my MK V as the old one had a crack. I made it out of a piece of solid brass bar and plated it with Replica Chrome form Gateros Ltd. The spring blade and the chain bow, I took from the old cap.
The groove that connets to the breather hole appears in the drawing sketch to be in line with the two screws for the spring blade attachment, but actually I made it square to these screw holes.

I attach my  drawing sketch for the petrol tank cap, and will try to post some photos also.

Regards
hoejmark

Hi Darryl,

Have a look at this thread. I think we decided that the TS/CW used the larger thread at the cylinder end, with the EW using the smaller.

https://www.douglasmotorcycles.net/index.php?topic=8919.0

The 7/16-20 thread is pretty common - it's actually a cycle thread.

Cheers

Leon

Hi thanks for the reply. I think, due to the saw cut along the length where they went slightly too far its a post factory mod but its not structural so I'll leave it as is.

Chris

Hi Chris

As you had no response can I suggest that it may have been modified to take some form of side stand? My son has a Z frame but the bike was built as an Aero 500. Whether this was done at the factory or by a subsequent owner is not known.

Roy

Thanks for the information, ill check out that B&B jet Data.