BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Rsmith123 on 04 Dec, 2020, 18:26

Title: C11 crank side play
Post by: Rsmith123 on 04 Dec, 2020, 18:26
Hello guys, just assembled crankcases back together and then found out I had quite a bit of side float, I have fitted a new bearing and oil thrower plate but used the old engine shaft distance collar 65-2048, it did appear to be slightly worn but thought I would get away with it. The crank is held by the engine shaft pinion which in affect stops the end float but that means the distance collar is free to move on the crankshaft. After measuring it up I found there is approximately 2mm gap. Not sure this makes sense, but fed up having to split apart. HELP!!!!
Title: Re: C11 crank side play
Post by: Ian C on 04 Dec, 2020, 18:45
I did a bit of research for the spacer (part no. 65-2048) and these dimensions came up. Do they match what you have?

ID           = 0.985 (25mm approx)
OD          = 1.310 (33.25mm approx)
Thickness = 0.330 (8.4 mm approx)
Title: Re: C11 crank side play
Post by: Rsmith123 on 04 Dec, 2020, 21:20
Your measurements are the same as my distance collar, I still can't understand why it seems short by 2mm. Thanks for information.
Title: Re: C11 crank side play
Post by: JulianS on 05 Dec, 2020, 18:37
When the cush drive nut is fully tightened the crank will be pulled right over to the drive side sandwiching the distance collar between the main bearing and the oil flinger which in turn is right up against the crankshaft. This locks the crank and the collar in place and eliminates end float.

The timing side pinion does not limit float.

Title: Re: C11 crank side play
Post by: Rsmith123 on 09 Dec, 2020, 20:53
Thanks, I now realise how it works, learning all the time.