The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: spottycat on 27.07. 2025 10:11
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Hi, Just spoken with SRM and they say there will be a delay getting new oil pumps made for the A10. I don't suppose there is anyone that bought one, ended up not using it and has one for sale? I know it's a long shot but thought it's worth the question. Cheers, Chris
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Have you considered getting your old pump refurbished, they,s a Guy on Ebay who offers this service, could be a solution until you obtain SRM pump. Just search BSA oil pump and his site appears.
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Thanks Billy. I didn't know about that guy but it is certainly a possibility. Cheers
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I just could not face paying SRM price for a pump when I restored my bike. I found a source of new iron pumps that were about half the price of the SRM ones. The chap that was selling them, (Bantam John) has since died I believe but it seems very likely that someone is cashing in on selling a replacement pump that costs less than the SRM one. If no other forum members can advise you on these you may have to wait for SRM.
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spotty cat give sheffield british motorcycles a ring they are based at stavely in chesterfield, bantam john used to run it but it is now being run by good helpful people . bantam john has stepped back after becoming ill.
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Sheffield British Motorcycles https://share.google/rd0tZyibVgkk8T09j
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Hepolite (Wassell) do a cast iron bodied version. Last time I looked this was also made of gold, being priced at a similar point with SRM.
Alternatives for us skinflints are a later body from an A65, along with its better gears, but fitted with the A10 nose and drive spindle. Later versions have cast iron bodies. Strictly a DIY effort and frowned upon by some, but the bits can be made to fit and this also avoids the MAZAC shape shifting problems.
Plenty on the Forum about pumps, selective assembly is how they did it, still works today with a bag of bits you can build your own. The gears are usually happy, binding comes from tightness in the drive spindle and nose where it runs.
From experience a bad pump has chips to the internal oilway webs and scoring to the gear chambers. The gears are usually OK, the idler spindle can be loose in the body and the base plate can be badly scored. I have come across input driven gears with a bent shaft, the drive tab is sometimes offset, and rotating the drive spindle half a turn can sometimes relieve a tight spot. Drive spindles worn to a knife edge and noses worn away where the timing bush has worn enough for the drive worm to run on the top edge. Failure of the castings is common, "pot metal "does not age well, bloating and flaking to be expected.
Gear pairs should match for number of teeth and profile. Later, A65 more efficient? pumps have fewer teeth on the gears, so called "petal" version. Seized and corroded pumps can be free'ed off in the oven or with a heat gun. Undamaged examples can usually be revived.
Swarfy.
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The A65 pumps with fewer gear teeth are the OIF iron ones. The gears are wider and don't fit the mazac bodies. They are also hard to find. Some photos of the iron pump below. They were a vast improvement on the mazac ones. The SRM pump uses the same sized gears with the same number of teeth.
The mazac bodies are sometimes found distorted by over tightening the retaining nuts. The gears in such pumps can be very tight and the assembly screws may be hard to push through then body.
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Thanks for those pictures Julian. Fewer teeth and a greater swept volume for a better output. Later type A65 pump also has an O ring seal on the drive spindle and the nose dowelled to the body. Gears and body as a set should interchange with the earlier A10 type pump, as all Mazac bodied A65 pumps to hand are dimensionally identical. Now we are down to just 11 teeth.
Early pumps have 15 teeth, reduced to 14 for 1956, so be careful if mixing and matching gears.
Swarfy.
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G'day Spotty.
Same answer from SRM I got a few years back. I got one from Austria I think. De Groot have one on their page (might be sold out). Do a search for BSA 42-0115.
A quick fix until you find one is to lap the plate and nose flat (remove the scoring made by the gears). You don't need to remove the gears just give it all a good blast of carb cleaner. If you do remove the gears mark them so they go back exactly the same way (tooth for tooth). When re-assembling tighten the screws little by little and spin the drive at the same time. If it binds back off and try again. I get it in one go sometimes but other times it might take 10 goes. Good luck.
Cheers
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Hello Spottycat
Sorry to hear you can’t easily obtain the SRM pump
Had mine for 10+ yrs and it pumps like a shithouse door in a gale.
Have you considered Draganfly ?
They used send you a re built pump if you send them your clapped out pump
Perhaps worthy of enquiry.
S
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Thanks everyone. Having got this far and sorted the bottom end I am tempted to hold out for an SRM. I know they are expensive but people seem to rate them and keeping the bottom end sweet seems the trick to keeping these old girls going. Cheers
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Cast iron pumps are available, branded Hepolite.
Recently purchased one for a B31; haven't fitted it into the bike yet. However appears to be made to a good standard.
Several suppliers are advertising the A10 version, but all I have checked are out of stock.
Cheers,
Richard
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It may have been a one off, but I read some where (a Facebook forum probably), that someone bought a Hepolite cast iron A10 pump and discovered that one of the oil hole drillings did not line up. Maybe this is the reason that they don't seem to be available?
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I enquired on availability with SRM just last night, and Stewart replied an hour ago to say he has just literally had a handful come in..
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Hi All,
A few years ago i was rebuilding an,Ariel Huntmaster, at the time there was no stock of SRM pump so the owner bought a hepolite one, on examination i found that the body fixing screw holes had broken through to an oilway! When i contacted the seller they immedietly sent a replacement and said dump the other! I didn't of course and think it would work fine of the offending screw was fitted with some sealer? I gave it to a friend sometime later...
However, the Huntmaster now wet sumps if left for a couple of months , where as my SR that has the SRM pump for 20 years plus does not!!
John
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Ooh! The postie has just been...
(https://i.postimg.cc/hjszsx1G/SRM.jpg) (https://postimg.cc/ft3RTVF4)