Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board A65 Primary Chaincase

Hi all,

I have a late A65 primary chain case, which has the small round cover for checking ignition timing and it also has what look like oil level and drain screws fitted directly in the casing, as opposed to the early ones (like on my bike) which use the casing fixing screws for these functions. I’ve attached some photos.

The casing has the number 71-1045 cast on the inside.

I would like to fit this casing on to my 1966 engine and was wondering if anyone could advise me if this would be ok, or is there any reason why it would not do the job?

I’ve not looked into it in great detail yet but I have seen that it has a hollow dowel on one of the fixing holes. I will either have to counterbore and ream the matching hole in the engine crankcase, or remove the dowel altogether. The original primary case on my bike has no dowels.

Any advice, or warnings would be greatly appreciated.

Thanks, Kev E

Fit it, it’s a good modification. Especially if you are running the standard wet clutch.

Thanks Allan, it looked like it would fit ok but I just wanted to make sure there was nothing that would catch me out.

Regarding the dowel. Would you keep it, or leave it out.

I’m a little mystified as to why there is only one dowel in the chaincase as I thought two would have made a better job of alignment. I’m assuming that’s it’s purpose?

Cheers,

Kev E

Hi

Don't worry about the dowel. However for your information the one dowel and the primary chain adjuster pivot pin also locates into the primary cover, thus acting as a location point.

regards

John

Thanks John,

I see what you say, that tensioner pivot pin will certainly act like a second dowel.

I think I'll leave it out, the current chaincase has worked well enough without it since 1966.

Cheers, Kev E

I have an idea that because the latter covers are a bit thicker that if you use one on an earlier motor that has had a cast iron oil pump retro fitted you need to use a Dremel ( or as English speakers would call it a die grinder ) or similar to relieve the cover a bit so it doesn't interfere on the pump, test the fit with no gasket to make sure there is clearance and dont just rely on the gasket thickness to provide clearance , its too marginal

something like that anyhow details are starting to drop out of my head but 95% im right ......can someone confirm this remark

BTW Kevin E ... i saw u liked one of my posts , glad we have buried the hatchet bro ... all good this end

Hey Ignoramus, hope you’re well buddy.

My post was concerning the primary drive side chain case, so no worries about oil pump clearance on that side of the bike.

Hatchet was never out, so no need to bury it.

I’m not the type to hold a grudge. We’re all bikers and BSA lovers, so live and let live I say.

Take care over there in NZ 👍🏻

This thread is about the primary cover....not the timing cover.

IN all the excitement i plain forgot ( inspector Callahan )

I’ll have some of what you’re smoking 😉 😂

Nice!!

I enjoy movies from the '70s primarily because of Technicolor.

I believe it was Lewis Carol that used to go down the bottom of his garden to find the special mushrooms that grew there

Refer to that hippy icon song White Rabbit featuring Grace Slick of Jefferson Airplane ..........Alice being 10 foot tall and all that

that's not of topic is' it ?

It is off-topic, as have a few been, and this one included, but if we can't have a laugh it would be a bit dry I think.
"Remember what the good book said".

I wonder what Shakespear was smoking when he wrote "Midsummer night's dream"