BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: DAVE BRADY on 06 Feb, 2026, 12:17

Title: C15/B40 sump plate
Post by: DAVE BRADY on 06 Feb, 2026, 12:17
Hi,

Has anyone found a better sump plate for the C15/B40?
Is there an aluminium one out there with a magnetic drain plug?  So far I have not found one.

Dave.
Title: Re: C15/B40 sump plate
Post by: rhyatt on 06 Feb, 2026, 13:19
I silver soldered a nut on mine to accommodate /create a drain facility
Title: Re: C15/B40 sump plate
Post by: limeyrob on 06 Feb, 2026, 15:31
28-0243 is a nice drain plug.  Its cycle thread.  Silver soldered nut works and you can drill the plug and press a neodymium magnet in.
Title: Re: C15/B40 sump plate
Post by: Mark Cook on 08 Feb, 2026, 11:08
I've been meaning to get around to it for about 20 years now, but up until recently there has been no demand for C14/B40 parts Dave.

Mark
Title: Re: C15/B40 sump plate
Post by: DAVE BRADY on 08 Feb, 2026, 14:39
Hi Mark,

There seems to be lot more questions re C15/B40 as these these smaller models are perhaps in more demand/use.
The leaky sump plate is a perennial issue re leaks, either the poorly pressed out plater or leaky thread being the main culprits.
My next move is to try making sure the plate is flat and that the stud threads are sealed in the case.
A drain plug would be a bonus but regular starting/riding usually reduces wet sumping.

Dave.
Title: Re: C15/B40 sump plate
Post by: Mark Cook on 09 Feb, 2026, 17:54
The draining back is more than likely a worn pump.
Give me a chance, they are also on the "to make list"

Mark