Primary Chaincase notch

[dsj666]

I was just looking at my chaincase from of the box of bits I have and it appears there is a notch out of the boss around one of the bolt holes.

It might be chain wear but looks quite neat and tidy and "official" although I'd expect oil to just leak straight out past the bolt!

Should this notch be there or do I need to repair it?
Or am I missing something?

Thanks

[Triton Thrasher]

It could work as a drain plug or a level plug, depending what height it’s at.

[stu.andrews]

I'm pretty sure that this is the primary chaincase level device.

[Swarfcut]

 Top Marks there. The notch sets the oil level for the primary case.  A fibre washer under the setscrew head acts to seal as it is tightened down.

 More detail elsewhere, all  well documented on the Forum about alternative ways of setting the level and the several confusing quantities of oil recommended to be used.

 Swarfy.

[dsj666]

Brilliant, thanks everyone!
That's what makes this forum so good, its a mine of information, and so quick! 

It all makes total sense now and I've even found the fibre washer..........part no 67-1709.

Yes, more info on this on the forum now I know what to look for!

Cheers 

[Greybeard]

Are you planning a BSA powered wheelbarrow? A BeezaBarrow?