Timing side screws

[Phil C]

The screws holding the timing side outer casing on my 1965 B40F are Phillips, or something similar. Is that what they would have been originally? Seems to me that an ordinary Phillips screwdriver won't give much leverage to achieve a  tight joint (of course you wouldn't want to be trying to get it too tight either.) I think it's also easy to round them off. The other side (primary chaincase) has Allen screws.  Phil

[Bess]

Hi Phil,
           They were originally Phillips.

I have changed to stainless hex head as I also have had issues 'rounding them off and damaging the plating leading to corrosion. I use a hex screwdriver to ensure I don't overtighten them.

I have loads of original BSA Phillips screws if anyone is interested.

Best wishes...

[Greenfield]

Hi Phil
Get yourself a set of stainless socket screws and use the correct size allen key. They won't round off but be careful not to exert too much force or you'll damage the casing. As long as everything's flat, there should be no problem forming a seal. Not as original but I personally think they look good.

[Bess]

Hi Phil,
            Sorry I meant to say hex socket, I don't use an Allen key on casing screws but a screwdriver as so:

https://www.ebay.co.uk/p/2254446685?iid=383753270134

Best wishes...

[DAVE BRADY]

Hi,

I use Allen keys but only the short side to tighten as much as I can just using finger and thumb and the long side is good for undoing as sometimes the screws can become a bit tighter during use.  For the inner case screws that need to be tighter I use the long side.  The screwdriver type for tightening the outer case screws is definitely a good idea to avoid over tightening.
It is also a good idea to clean out the threads really well so that the screws tighten against the case and not against compacted goo and bits of gasket in the bottom of the hole.

Dave.

[DANFINN]

I would be interested in some Phillips screws. I think they look much better than Allen type.

I make sure my Phillips head fits tight and all goes well

[leon bee]

Pozidrive screws. New screws and a #3 Pozidrive tip, they'll work well and look good a long time. When we were kids we all thought they were #3 Phillips and stripped the heads out.

[Phil C]

I notice the allen screw drivers on Bess's link (thanks, Bess) are metric sizes. Does anybody know what the threads on the screws are? I would have thought imperial, ie BSF or BSCy?  (1965 B40F timing side outer cover) Phil.

[Calum]

I notice the allen screw drivers on Bess's link (thanks, Bess) are metric sizes. Does anybody know what the threads on the screws are? I would have thought imperial, ie BSF or BSCy?  (1965 B40F timing side outer cover) Phil.

Going into aluminium I suspect they will be Whitworth

[Phil C]

Makes sense. If I'd taken one out before asking I guess I'd have noticed it was a coarse thread rather than fine!  Thanks, Calum.
  Phil

[Bess]

Hi,
    Bizarrely a high probability they are Phillips CEI:

https://www.draganfly.co.uk/bsa/bsa/b40/category/1187-1187-

Best wishes...

[Phil C]

Hmmm, which I think is the same as BSCy?  Phil

[Bess]

Hi Phil,
           They are interchangeable, the thread forms are slightly different though.

Best wishes...

[Phil C]

I've just noticed something in my BSA Instruction Manual (which is for the C15 Star, C15 Sportsman and B40 Star. Mine is a 1965 B40F. )
On p.40, under a sub-heading "Starter Pedal Spring", it says "The recessed-head screws retaining the cover require a screwdriver of a special type and a standard screwdriver must not be used." Now I've no reason to doubt Bess's assertion, above, that the screws were originally Phillips, but would BSA have described Phillips screws like that? Were Phillips screws that uncommon back in the mid-60s? I ask just out of interest.  Phil

[Phil C]

Thinking about it, I reckon the answer is probably yes. The wording in the manual sounds now a bit comically dramatic, but maybe few people back then would have known what a Phillips screw was.  Phil