The BSA A7-A10 Forum

Technical (topic titles must be descriptive) => Gearbox, Clutch, Primary => Topic started by: Dave on 23.03. 2021 20:17

Title: Unsure which outer clutch cover is right for my bike build?
Post by: Dave on 23.03. 2021 20:17
Hello,

Please can I ask for advice on the two covers that I have. I really don't know why they are different or which I need to fit. One has a extra hole and seems to have a breather for some reason too.

The Engine is a 1960 A10 the frame 1954

I'm guessing the one with only one hole is the older one, but its a bit of a mystery.

Many Thanks
Dave
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: Roger (Doomtrainbarx) on 23.03. 2021 21:07
The extra hole is for the 4 spring clutch adjustment - it is the later cover.
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: Dave on 23.03. 2021 21:29
Hi Roger, Thankyou for the information.
The bike has a upgraded 4 spring clutch so you'd recommend the later cover? Do you know roughly when the upgrade was introduced at BSA? I need to find a plug for it if so, as I've only got the bigger one. Another missing part to look for!!

Dave
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: Jules on 23.03. 2021 23:51
"seems to have a breather for some reason too." - where is the breather Dave, (just for interest)??
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: BritTwit on 23.03. 2021 23:54
I believe the 4 spring clutch first appeared in the 1960 A10 parts book.
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: BSA500 on 12.05. 2021 13:05
I think its not a breather its the oil drain bolt that is being referred to
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: Joolstacho on 13.05. 2021 01:15
Yes the later one is also more useful because it has the combined oil drain plug and oil level plug, so you don't even need to measure the oil going in when you top it up.
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: RichardL on 13.05. 2021 05:07
Yes the later one is also more useful because it has the combined oil drain plug and oil level plug, so you don't even need to measure the oil going in when you top it up.

No need to measure in the oil on the older version. Leave out first 1/4" screw behind the lower 5/16" and wait for overflow. Put it back when done (the screw, not the dripping oil). *smile*

Richard L.
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: tomkilde on 07.08. 2021 23:59
My 1961 SR restoration project came with a 6-spring clutch and a primary cover with an adjustment hole.  Looking at this thread, it seems they don't belong together, and it probably explains why the clutch nuts have gouged a path through the threads on the back of the adjustment hole.  I assume I need to source a plain primary cover, without a clutch adjustment hole.
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: berger on 08.08. 2021 00:20
that could well be past damage when the clutch nut has come loose. mine has the same cover and when i had the six spring on it was ok but it had previous damage like yours
Title: Re: Unsure which outer clutch cover is right for my bike build?
Post by: Jules on 08.08. 2021 01:40
There are lots of covers out there with that damage, when I was looking years ago thats all that I could find. I have one with a horrible welded up hole too, apparently getting a clean weld on these old cases was(is?) difficult because of the oil contamination in the pores of the metal casting.....