Below are pages from Glass's motorcycle check books from the 1960s.

You can see it was not that popular, the B40F SS90 between September 1964 and August 1965 from engine 101 to engine 295.

The earlier engines I dont think you will see a B40SS number above 600.

US models not included in these figures.

You will not find out how many are left or registered.

The 15 thou needs to be set when the cam is on its base circle, that is in the normal position for tappet setting - set inlet when other inlet is fully open.

Sorry to bring this up, again.
Now, have I got this right?
I have read all that I could find on this subject, but some things are still confusing.
When doing this job, some say the 'clock' should be on the valve collar or on the rocker arm adjuster.
Others say, this is incorrect because the quoted figures are for the pushrods/tappet followers.

Another thing is, people talk about 'lift', do it at .040".
Lift meaning valve lash? It could mean, turn the crank + .040" @ 0.015" lash, after the needle begins to move and read the degree-wheel?
Also, taking the WSM figures for inlet: open 51* BTDC, close 68* ABDC at 0.015" lash.
Using these figures, we have 51+180+68 = 299*. 299/2 = 149.5*.
The cam lobe centre is given as 98.5* crank ATDC, so for the cam centre we subtract 51* from 149.5* = 98.5, OK fine. (this MAY be the lobe peak, but not neccessarily).
But, the quietening cam ramp needs to be avoided, so the measurements need to taken at .040" lash, not at 0.015"
OK so far?

Hello,
I would appreciate any advice about suitable tyres for my 1970 B25 Starfire. I returned to biking 18 months ago but have only done a few hundred miles on the Starfire and still feel a newbie, so apologies in advance if my questions are at a beginner level.

The front tyre is a Kenda 3.25 x 18 and the rear a Mitas 3.50 x 18. I want to renew the rear tyre, my priority being roadholding and grip. I live in a rural area so local roads can be a bit greasy from the passage of agricultural machinery. My question is

a) is it important to have the same make front and rear? If it is, then as Kenda don't appear to make a 3.50 x 18 I would need to replace  both, and

b) which makes would you recommend for good roadholding. As I don't do many miles longevity and wear is not so important as roadholding. I'd rather not have to spend a lot but will if more expensive brands give better grip.

I would be grateful for any advice from more experienced members.

Thank you,

Hugh

Hi Jim, that's brilliant, thanks.
Sorry I meant "don't want to" as in "you don't wanna do that!" I have no strong emotional attachment to either solution
OK, so set timing rotor mark to pointer, use your photo for reference when fitting. Then strobe!
Thanks again,
Dan