BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: Caulky on 11 May, 2017, 20:13:17

Title: 1971 A65L Camshaft nut
Post by: Caulky on 11 May, 2017, 20:13:17
There is no torque figure for this nut.
How tight should it  be and how much float?
At the moment I have about 1/16th" lateral movement.
I had to manufacture a woodruff key, because the keyway is 5mm wide?
I think I over-tightened it, the first time and it became solid.
Title: Re: 1971 A65L Camshaft nut
Post by: JulianS on 11 May, 2017, 21:16:20
The cam end float is taken up by the spring between end of shaft and the breather disc, when it is assembled in the crankcase.

The workshop manual simply says "NIL - spring loaded" (section GD5 in the OIF manual)
Title: Re: 1971 A65L Camshaft nut
Post by: Caulky on 12 May, 2017, 10:22:14
Thanks for your reply Julian.
I can feel the spring when pushing the shaft/pinion inwards.
But, the cam pinion is slightly out of alignment with the idler pinion.
Should the pinion be in contact with the bush outer or should there be a gap?
I`ve a feeling there should be a small gap because if its in cantact it would get hot and wear.
Title: Re: 1971 A65L Camshaft nut
Post by: JulianS on 12 May, 2017, 12:32:19
I would expect there to be a slight gap when the cam is pushed outwards by the spring.

Just make sure the pinion is positioned right up to the shoulder on the shaft cam.

Should the pinion move into contact with the thrust face of the bush I doubt it would get too hot. Consider the A10 setup where the pinion is pushed tight against the bush by the breather and cork washer - that does not cause a problem.
Title: Re: 1971 A65L Camshaft nut
Post by: Caulky on 12 May, 2017, 13:10:24
Thank you, will do.