I've just bought a B40 U.S. import for restoration which was advertised as a Sportsman - and externally looks to be right.
However, on checking the numbers I find that it's actually a 1964 B40 Super Star - the frame No is B40 7468 and the engine B40 B 1414
I can also see that it's fitted with the 389 carb and has the 41-211 head which indicates the SS90 engine - all good so far although there is no 'HC' stamping.
I've yet to strip it to check the piston and camshaft but wondered if anyone had any info on this particular model?
It seems that in '64 there was also a Sports Star U.S. model with B40 SS prefix so wondering if the engines were a different spec and why these models only seemed to last for one year before being replaced by the Sportsman in '65 with a B40FB prefix. Was this just BSA marketing or real technical changes?
Finally - I'm planning to restore this with a bit of modernisation - the trouser forks and headlamp will be the first to go and I'll be looking to replace with some chromed covers with ears to take a chromed headlamp shell - not sure what's available but wondering if T140 covers might fit?
Many thanks,
Bernie
The US version of the B40 SS90 (Sports Star 90) had engine prefix B40B and was sold as the Sportsman.
Photo from the 1964 US East coast catalogue.
Thanks Julian, spanners have been flying and it's looking promising. I have a 40-478 can fitted which doesn't seem to appear in any of the main references I use (Rupert R, Draganfly) but the profile looks to be right and 40-477 was used in the SS90 so hopefully it's good.
Interesting that BSA used so many different cam and follower profiles though.
Still have to check the piston.
Cheers,
Bernie
40 0477 is the part number for the cam complete with the pinion and key. 478 is the bare cam no pinion.
You can download a copy of the B40 parts book from the unit singles site.
www.bsaunitsingles.com/spares.htm
The SS90 parts different to the standard B40 came on the parts bulletin below.
Managed to get the head and barrel off today to find that it's fitted with a +0.5mm piston stamped BSA 41-253 which I think is the HC variant.
Rings are very worn and exhaust valve burnt but other wise looking in very good nick and piston and bore just about within tolerance so I may get away with just a new set of rings.
One thing I did find was that it still has the original flexible oil pipes fitted - steel reinforced and crimped at both ends so I had to cut the crimp to disconnect. I was hoping to re-use them but when I removed the feed line I found that it was cut through where it runs through the tinware just below the ignition switch, presumably due to vibration against the sharp edge. Wondering if that's a common problem with B40s and C15s? Will obviously be fitting a grommet when rebuilding.
Cheers,
Bernie
Restoration now complete and waiting for the certificate for DVLA :)
I'd be very interested to know the difference between the B40B engines used in the 'Super Star' and the B40SS engines in the 'Sports Star' models - both of 1964. Looking at my 'B' it seems to have all the SS90 parts so wondering if it was just down to compression?
Cheers,
Bernie