Now in my ES2 ('61) rebuild, another query - and I thought it was an easy job when I first saw the bike.
Turning the engine over - not running - oil is running out of a small tapped hole on the timing side crankcase. It is situated behind the timing case cover, pointing rear and down - about 8 o'clock - mainly hidden by the frame tube.
It seems to be 9/32", I can't see what TPI, probably BSF or Cycle (1/4" is too small and 5/16" is too big).
It is not shown in any of the exploded views I have seen and no such size is shown in the Norvil spares list.
What is it for and what do I do about it?
On Plate "A" of the spare parts booklet for the '55 ES2 it shows an un-numbered grub screw at that point - just below the oil pie connections. It may well be a tapping hole for something inside the crankcase. On te other hand if the hole is at the bottom of the timing chain case it is a drain outlet for oil coming through the inlet camshaft bush to lubricate the timing chain. Hope this helps.
Thank you George, it is not the distributor chain chest drain hole - that points vertically down.
I only have the 1957 parts list for 88, 99, ES2 and model 50.
Plate B does not show any such grub screw. Nor does the Andover Norton exploded drawing.
I suspect it must be an access hole for drilling a passage in the crankcase during manufacture, and was never intended to be taken out.
All I have to do now is find a grub screw 9/32" x ??
Thank you again.
To continue our little chat, I made a mistake, the oil drain in the distributor chain cover does not point vertically down.
However, the hole I am referring to is the one in the crankcase at the rear, angled down at about 8 o'clock.
I have seen a 19S which also has this tapping point, with a stud screwed into it. I can have a stud made 9/32 x 20tpi but I need to know how long it must be. If I make it too long it could block some aperture in the case. The 19S I saw has the older frame making it impossible to remove the screw/stud with the engine in place.
Can anyone tell me how long this stud should be? It would help me get this problem solved.