Paul, I second that about the advance/retard lever.

If you have a mixture of parts from different years, then you can get problems. The lenghts of the levers might vary.

I found a french coin in the frontfork of my model A. It worked fine.

Waller says: 1,3745 -- 1,3750

I have seen 2 different types of springs. The old ones were wound by 1,8 mm thread. The new ones from 2 mm.

On a bike with shell bearings, I will always use multigrade oil.
20/50
Knud

Yes!

Which number do you like most?

You need to talk to your Ariel in the same way as you are talking to the plants in your windows.

Many years ago, when I restored my cast iron Sq4, I decided to reline the cylinders back to original size. Since then I have had on my shelf a set of usedd pistons in a big oversize; about 67,4 mm. I took measures of them in 2 directions. They are coming here: Nr1: 67,29 - 67,39. Nr2: 67,30 - 67,40....