BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: Nigelbarber on 06 Jul, 2024, 22:18

Title: A65 not scavenging-oil over the back tyre-any ideas why?
Post by: Nigelbarber on 06 Jul, 2024, 22:18
Hi all, following up an earlier post I'm looking for advice. I have an issue with an A65, and I recently fitted a new SRM oil pump. Took for a long fast 70mph run on dual carriage way, everything fine. Oil pressure 40 psi at 4000 rpm.
A few days later I went out, quite a hot day, mostly running at low speeds due to traffic. After about 10 miles I opened it up a bit, oil pressure started dropping far below normal, and then it dumped oil over the back tyre causing a nasty slide. I stopped and checked the oil tank-empty. We later found the crankcase was full of oil and I assume it was being thrown out of the breather on the camshaft as this exits near the gearbox sprocket.
Has anyone experienced this and if so what was the cause? The oil return to the tank seems fine, I know there is a bit of wear in the main bush, but it's not excessive-and it never did this with the old oil pump. Any help would be appreciated as I can't risk it happening again, it was really scary when it let go.
Title: Re: A65 not scavenging-oil over the back tyre-any ideas why?
Post by: Edwards on 07 Jul, 2024, 05:35
Hi
That's very strange SRM pumps are all bench tested before being sent out . Think j would be going down the route of checking the ball valve in the pick up pipe it might have stuck on its seat or even picked up some foreign body  that be dislodged.in the oil system. 
I once had a similar problem to you but with an oil in frame triumph what frothed the oil on a long run and leaked oil everywhere.  That I found to be a blockage in the pump drilling. Good luck hope you sort it fast Mark .
Title: Re: A65 not scavenging-oil over the back tyre-any ideas why?
Post by: Ted_Flash on 11 Jul, 2024, 10:12
I had similar with an A65 - it was down to debris on top of the sump gauze filter.  In my case the previous owner had overdone the silicone sealant.