If you have pattern fibre plates that are too thick you need to leave two plates out...From your dimensions each of your plates is oversize by 1/64" (.0156")...There are 8 plates so the total amount of surplus plate thickness is approx. 8 x .0156" or .1248" (1/8")....
So, leaving out two plates (one fibre and one steel) will restore the plate stack to pretty much the correct height...
Therefore this will have no effect on either the spring pressure or the proximity of the pressure plate/nuts to the outer cover, nor should it have much effect on pushrod length...However, a new pushrod should be fitted if it is required to achieve the correct adjustment of the clutch operating arm at the other end of the gearbox....It is important that the arm is correctly set to achieve maximum lift and that there is free play in the cable when the clutch not being lifted..
Check the free play at the operating arm as wear in the handlebar lever pivot can give a false impression...Also ensure the ball bearing in the clutch operating arm is unworn, of the correct size, can move freely and is lubricated with a little grease...
The clutch pushrods are not prone to flexing as long as everything is set up correctly and a standard length of silver steel (13") can be used to make any BSA heavyweight single pushrod when cut to the appropriate length and heat treated......
Check that the clutch plates are lifting evenly when the clutch is pulled in...If they are not a new spring will be required or you must make the REME modification to the spring nut to achieve that condition. When placed on a flat surface and checked with a straight edge the ground ends of the clutch spring should be parallel...After extended use the springs tend to settle out of parallel and the consequence is uneven lifting of the plates...Check that the spring itself is within the wear limits laid down...A worn or weak spring can also lead to clutch slip...
Also check for wear in the clutch basket and centre...These become 'notched' by the metal plates over time and the plates can then get caught up in the resultant grooves...Sometimes this prevents the plates going fully together under spring pressure resulting in clutch slip. The basket generally suffer from more wear than the centre in my experience...
Any notching can be carefully removed by filing, removing the minimum to clean up the surface. Try to remove the same amount of material off each slot if this work is carried out to maintain contact on all the plate 'tangs'...Ian
