The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Flash Chris on 21.04. 2026 22:22

Title: Sump scavenge pipe position
Post by: Flash Chris on 21.04. 2026 22:22
Is the scavenge pipe in a fixed position? I have an SRM sump gauze but the hole doesn’t line up with the end of the pipe and wondered if it’s possible to adjust the pipe. Or maybe it’s just the wrong gauze…definitely for an A10 tho…I’ve turned it and flipped it over to no avail. Just another shoddy aftermarket part?
Title: Re: Sump scavenge pipe position
Post by: berger on 21.04. 2026 23:19
does the old plate fit ok? if so it's the new one , if not the pipe has been knocked about when bare cases have been left without the sump plate on.
Title: Re: Sump scavenge pipe position
Post by: muskrat on 21.04. 2026 23:46
G'day Chris.
I have the SRM sump & gauze on both mine. I vaguely remember having to tweak one of my pipes to fit.
You can very carefully tweak the pipe a couple of mm. 
Cheers
Title: Re: Sump scavenge pipe position
Post by: Flash Chris on 22.04. 2026 07:03
Good shout berger, I’d meant to do just that last night but tiredness/darkness/black hole garage syndrome all got in the way!
I’ll check later, hoping it’s musky’s scenario and not berger’s, I don’t fancy another engine strip down so soon …  *eek*
Thanks guys.
Title: Re: Sump scavenge pipe position
Post by: CheeserBeezer on 22.04. 2026 08:16
The pattern gauzes currently available don't fit the pipe if it is in its original position. As Berger says, you can bend the pipe SLIGHTLY but, as it is shrunk or cast into the crankcase half it is important not to create an air leak at the join. I recently fitted an SRM gauze and had to file all the holes to enable the gauze to shift sideways to get it to fit. UGH! Pattern parts! Same old story!
Title: Re: Sump scavenge pipe position
Post by: Rex on 22.04. 2026 09:39
When my engine was apart I made a new plate from sheet brass with brass gauze soldered to it. The hole for the pipe was reinforced with two copper washers soldered in place.
It has the added benefit that the base gaskets clamp onto flat sheet rather than the old coarse gauze, helping to reduce oil leaks from this area.
I really wouldn't fancy tweaking 75 year old MS piping though. *eek*
Title: Re: Sump scavenge pipe position
Post by: Flash Chris on 22.04. 2026 10:35
I really wouldn't fancy tweaking 75 year old MS piping though. *eek*
Same  :!
Title: Re: Sump scavenge pipe position
Post by: Joolstacho on 23.04. 2026 00:56
I bought a nice finned sump plate, but it didn't come with a gauze. I attempted to make one like Rex, but found it very difficult to solder the gauze nicely. Tried various solders but. Strange, I'll have to do some more tests.
Title: Re: Sump scavenge pipe position
Post by: Flash Chris on 23.04. 2026 07:15
So the old one piece sump/filter still fits fine, leading me to believe the new one is a problem. Manager to file the mounting holes as suggested by Andrew which worked in getting the hole in th gauze aligned with the pipe but now the embossed circular lip of th filter interferes with the edge of the crankcase cutout. Not sure that will be easy to make oil tight and these bikes have enough problems in that respect without me adding to it!  :!
Title: Re: Sump scavenge pipe position
Post by: Triton Thrasher on 23.04. 2026 08:33
Can’t you just bend the gauze, to put the hole in the right place?
Title: Re: Sump scavenge pipe position
Post by: berger on 23.04. 2026 09:31
this thread has just jogged my senile old black&tan fogged memory , i remember now when doing the berger build i had to alter the gauze hole in the srm one because of this problem. at the time i was thinking maybe the pipe had received a knock in the case i was using and if i had tried an old one i would have got the answer. so it seems some of these gauze plates haven't been made correctly  *pull hair out* *problem* *bash*
Title: Re: Sump scavenge pipe position
Post by: Flash Chris on 23.04. 2026 10:31
Can’t you just bend the gauze, to put the hole in the right place?
The gauze is flat so no bending possible. Altering the stud holes allows movement but then the raised edge around the gauze fouls on the crankcase.
Title: Re: Sump scavenge pipe position
Post by: KiwiGF on 23.04. 2026 10:51
Is the scavenge pipe in a fixed position? I have an SRM sump gauze but the hole doesn’t line up with the end of the pipe and wondered if it’s possible to adjust the pipe. Or maybe it’s just the wrong gauze…definitely for an A10 tho…I’ve turned it and flipped it over to no avail. Just another shoddy aftermarket part?

My experience is that the scavenge pipe is glued into the case, it comes loose when its warmed up. I used a loctite product to stick it back in, after my machinest guy returned the case with it removed (as he had to machine the sump plate faces flat as I had mismatched cases)
Title: Re: Sump scavenge pipe position
Post by: Triton Thrasher on 24.04. 2026 09:14
Can’t you just bend the gauze, to put the hole in the right place?
The gauze is flat so no bending possible. Altering the stud holes allows movement but then the raised edge around the gauze fouls on the crankcase.

You make it sound like someone is selling parts that don’t fit!
Title: Re: Sump scavenge pipe position
Post by: BSA500 on 18.05. 2026 13:27
When I put my finned alloy sump plate on, the gauze was fine but the magnetic drain plug fouled the pick up pipe so badly I ended up flipping the sump plate around. When I told SRM about this they said there must be something wrong with my pick up pipe. Er no the original BSA plate fitted fine. I gave up and left it as it was.
Title: Re: Sump scavenge pipe position
Post by: chaterlea25 on 18.05. 2026 21:19
Hi All,
It has been written in Stone *ex*
DO NOT fit the magnetic drain plug near the pickup pipe

John