BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: watts on 01 Aug, 2026, 12:06

Title: 1970 A65T Cover
Post by: watts on 01 Aug, 2026, 12:06
Hello

I have rebuilt my engine and mounted it and fitted the timing and clutch side and released I maybe should have put this on before I fitted the engine.
I cannot get to the top screw.
I have remove clutch sprocket cover plate. I had to remove gear cluster to get sprocket off and I still cannot get it in.

Am I missing a trick, It crossed my mind the bolt may have been mixed up when I took it apart.
I think it is 2BA is this right? And how long?
I also notice in my 1970 original part catalogue has onlythe two bottom screws, but Draganfly part and diagram has 3, I assume this was later improvement?

Any suggestions, it maybe it is just a pain perseverance is needed?

Thank you
Title: Re: 1970 A65T Cover
Post by: limeyrob on 01 Aug, 2026, 13:49
I think it will rattle without that top screw.  I take it the engine plate is in the way?  Thread list shows 2BA x 21/64.  Can you get a hex head or Allen set screw in?
Title: Re: 1970 A65T Cover
Post by: watts on 01 Aug, 2026, 14:43
Thanks, no I removed that also.  Maybe I'm just not dexterous enough. Fat fingers!!
Title: Re: 1970 A65T Cover
Post by: Ian C on 01 Aug, 2026, 16:29
The top screw for this plate although the same 2BA thread as the 2 bottom ones is a hex head (BSA part no. 40-3044) as opposed to pozidriv for the 2 lower ones (part no. 97-3894) and is also listed for other uses on BSA and Triumph machines. All 3 fasteners should also have lock washers (BSA part no. 29-3319). HTH
Title: Re: 1970 A65T Cover
Post by: iansoady on 01 Aug, 2026, 16:38
I may be wrong but surely Phillips not pozidriv? Not to be confused with JIS of course......
Title: Re: 1970 A65T Cover
Post by: Superflash on 01 Aug, 2026, 21:28
As a matter of interest, whats the downside to just leaving it off?
Title: Re: 1970 A65T Cover
Post by: limeyrob on 02 Aug, 2026, 13:26
Engine gets dirtier.
Title: Re: 1970 A65T Cover
Post by: cdsdorset on 02 Aug, 2026, 15:39
You can get the bolt back in. Just takes time.
Title: Re: 1970 A65T Cover
Post by: watts on 12 Aug, 2026, 13:48
Thanks I have managed it.
Title: Re: 1970 A65T Cover
Post by: ChrisG on 14 Aug, 2026, 14:10
Many A65/A50's I've seen have this plate missing. I ran my OIF A65 for years without one. Yes, the only issue is the muck, rainwater etc. can get in but as we mostly ride in fair weather it's not critical
Title: Re: 1970 A65T Cover
Post by: DAVE BRADY on 19 Aug, 2026, 12:56
Hi,

Never had this plate fitted and over many miles no associated problems. It may keep some dirt out but also hinders cleaning in and around the sprocket.
Unlikely to get rain water in there unless you splash through a deep puddle and it would soon run out again. 
Keeping your chain properly adjusted and lubed is vital.

Dave.
Title: Re: 1970 A65T Cover
Post by: EDDIE SIMPSON on 22 Aug, 2026, 23:08
i fitted the tray to my a65 as i thought it was to protect the casings if a final drive chain snapped.
although i have never had that happen.
Title: Re: 1970 A65T Cover
Post by: DAVE BRADY on 23 Aug, 2026, 06:37
Hi,

Usually if the chain goes it gets wrapped arpound the gearbox sprocket and is more likely to damage the back of the crank case.
If the chain did snap and was stuck not too tightly this plate if fitted would hinder attempts to free the chain as without it there is a bit of access to get something there to poke it out.

Dave.
Title: Re: 1970 A65T Cover
Post by: limeyrob on 23 Aug, 2026, 17:13
Having had a chain snap I found it was the chain guard that took the beating.  Not fixed rule but that was my experience.