Hello everyone, On my 1965 B40F I have just been fitting the primary chaincase cover, and I've stripped the thread on the chain oiler. I'm not worried about the oiler itself, as I read that they're not really needed and can even be a pest. The Allen screw goes straight through clearance holes to thread onto it, and in so doing helps to secure the cover. So I need something to use instead of it, which will not allow oil to leak out of the primary chaincase. I guess a nyloc nut won't be oiltight. I'm guessing something like a piece of brass hex bar with a blind threaded hole (and a fibre washer)? I don't have a lathe or pillar drill or anything like that, sadly. Any ideas please?
The thread on the Allen screws is 1/4" x 26 tpi, so either BSW or BSCycle, which I think are almost identical (I think just the thread angle is different? - 55 and 60 degrees) - I don't know which is correct. Anybody know?
Thanks very much in advance. Phil.
Easiest way is a fibre washer and 26 tpi nut.
I've done that, with a nyloc nut, but thought the oil would simply travel along the thread and out. But then I guess no more than would escape via an oiler. Thanks Julian. Phil.
You could put a drop of loctite on the thread should the oil find its way along it.
Good idea, thanks. Does anyone know what the Allen screws' thread is: Whitworth or Cycle?
1/4 inch 26 tpi threads can either be BSF (British Standard Fine) or BScy (British Standard Cycle sometimes called CEI for Cycle Engineers Institute).
The slight difference in thread angle will not really make any difference to basic fasteners and they effectively interchange. I suspect that threads sold as 1/4 cycle may be actually be 1/4 BSF.
BSW is a coarse thread, 1/4 being 20 tpi.
Yes, BSF not BSW, thanks Julian, I must have misread my Zeus book.
I've always been a bit surprised that Zeus books don't include Cycle threads.
Phil.