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BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: DAVE BRADY on 03 Feb, 2025, 19:40

Title: A65 oil pressure switch
Post by: DAVE BRADY on 03 Feb, 2025, 19:40
Hi,

There are parallel and tapered thread varieties but which one for which year of A65?

Dave.
Title: Re: A65 oil pressure switch
Post by: Ian C on 04 Feb, 2025, 12:52
AFAIK Dave and there may be variances due to manufacturing difficulties, the 1969 model year A65's were fitted with a 5PSI rated switch (BSA no. 19-6504, Lucas 5307/05) which had a 1/8" x 27 NPTF thread. This thread was tapered and classed as 'Dryseal' so evidently no PTFE tape or sealant was required (which I find difficult to fathom)..
From the 1970 pre-OIF model year and then the OIF models BSA fitted a 7PSI rated switch (BSA no. 19-6508 Lucas 5307/1/07 or 5300/07) which had a 1/8" x 27 NPS thread (straight) which had a seal between the switch body and crankcase. HTH
Title: Re: A65 oil pressure switch
Post by: DAVE BRADY on 04 Feb, 2025, 12:59
Hi Ian,

Thanks.  I think I need the later one.

Dave.
Title: Re: A65 oil pressure switch
Post by: peasy on 04 Feb, 2025, 20:29
My 71 OIF is straight thread.
Title: Re: A65 oil pressure switch
Post by: DAVE BRADY on 04 Feb, 2025, 22:59
Hi,

I have late cases so the straight one will be correct.  Thanks.

Dave.
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