BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: Cullenexpress1960 on 04 March, 2018, 14:45:22

Title: SRM A10 650 twin
Post by: Cullenexpress1960 on 04 March, 2018, 14:45:22
Hi Guys
New to the forum and the BSA fold so please excuse any ignorance before I start !!
I have just purchased a 1960 A10 650cc twin that had a total restoration by SRM to look like a gold star back in 2001
I have invoices back from 2001 for total engine build totaling 2800 this includes a SRMNR3 NEEDLE ROLLER BEARING CONVERSION also fitted BSA recon oil pump / SRMCR1 sump filter kit is this the plate attached to the sump plug ?
A few questions as the bike has only covered 500miles in the past 17 years and I would like to recommission correctly over the next few winter months 
1, Has the oil specifications changed at all since this rebuild in 2001 the engine guarantee certificate ( although way out of warranty !) states recommeneded oil
Engine General use SAE 40 or SAE 50 for +25C ? I will only use the bike May to Sept ? but not sure we get many +25C days what oil does everyone use I spotted Morris Golden Film SAE 40 but its a brand I'm not familiar with.
Gearbox EP90
Clutch 10/40 or 20/50
2, The SRM notes mention no Anti-syphon/drain valves tobe used on oil lines ( I was thinking about fitting one as the previous own told me it would wet sump if parked for a few months ) are they not a good idea Or have they improved function since 2001 ? Also mentions not to fit filter kits on feed and return lines ?
3,Spark Plugs seem to be NGK B8ES are they correct ? alloy head fitted

Title: Re: SRM A10 650 twin
Post by: Editor on 05 March, 2018, 15:16:01
Re your questions regarding oil. On SRM recommendation, I have used straight grade SAE 50 in my Thunderbolt for the last 10 years (changing it regularly of course). In that time it has done 13000 miles and I have just checked the bores and big ends and they are showing no signs of wear.  I do have a remote screw on cartridge oil filter fitted, which must have helped. I use Morris's Golden Film available from all good Motor Factors. Main thing is to be sensible with the oil changes. Some people change it every year without fail but if you've only done 500 miles, that's a bit over the top in my book. Mine has been changed approx every 1500-2000 miles, dpending on how much I've put in during that period (A65's do tend to use oil usually via the valve guides). Other recommendations re Gearbox and primary chaincase are correct.
Re the Anti Syphon valves well, the jury has been out on these for years. The A10 does have a check valve in the oil feed internal galleries which, I believe is the usual ball and spring but is got at from inside the crankcase so not easy to sort out if it doesn't hold the black stuff back. I would assume that SRM would have re-seated this as part of the rebuild, so I suggest you try it and see. The beauty of the SRM sump plate is the drain plug. If you have left it standing for a couple of weeks, undo the drain plug and see how much comes out. If you use the bike weekly, its unlikely that much will have got past the 'overhauled' oil pump anyway'.
Hope this helps!!
Title: Re: SRM A10 650 twin
Post by: Cullenexpress1960 on 05 March, 2018, 18:15:46
Chris thanks for your reply
Ive only just got the bike so Im hoping to do a little more than the previous 2 owners of 30 miles per year !!
Yes I will change the oil and see how the wet sump issue goes