The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: wortluck on 06.05. 2018 17:44

Title: Iron filings on magnetic sump plug
Post by: wortluck on 06.05. 2018 17:44
adm edit: Drifting offtopic, split from "Help - bike's gone bang!" (As always, thanks again for your sound advice)

By the way, the bits of fine iron filings on my magnetic sump plug - where do they come from??
Title: Re: Iron filings on magnetic sump plug
Post by: a10gf on 06.05. 2018 20:58
May be normal if engine have had some work done not that long ago (parts bedding in), magnet will do it's job for steel (and on may see some brass residues shimmering in oil).

If lots of filings and it increases it may be time to investigate, for example I had crank shims ending up on the magnet (check the end play).
Title: Re: Iron filings on magnetic sump plug
Post by: muskrat on 06.05. 2018 21:00
G'day wortluck.
How long is a piece of string? Lots of things in there to wear and produce iron/steel dust. Timing gears, cam and followers, drive side bearing, piston rings and bore. All motors produce a little but if there any bigger than powder I'd look further. If it's big bits it will be the drive side shim breaking up.
I'd clean everything thoroughly, flush the lines (in and out), remove the tank and clean out all the old crap (I use pressure washer). Fill with new oil and check plug in another 100 miles then again at 500.
Cheers
a10gf got in 1st.
Title: Re: Iron filings on magnetic sump plug
Post by: wortluck on 06.05. 2018 22:14
Cheers Musky and a10gf.  Not big bits, just really, really fine filings, and I've had the 'shimmering' stuff too.  I've done about 3.5k since the rebuild (not much, I know, but where's the time??).  Cleaned everything when I stripped the mag drive pinion and there's almost nothing on the sump gauze now (just a bit of gasket sealant).  In the end, I cleaned the gauze 8 times and ran off the oil from the sump.  Tank's been done twice, so it's as clean as I can get it.  I'm reassured the filings are normal - just wanted to check.  Frequent oil changes and keeping everything as clean as possible seems to be sensible.

I now know how to time the beastie up, so valve clearances are the next challenge.  Not sure I'm quite ready to tackle full engine/gearbox rebuilds just yet but the more things that go wrong, the more opportunities to learn are created! *eek* *beer*
Title: Re: Iron filings on magnetic sump plug
Post by: duTch on 06.05. 2018 22:37

 Good you got it all sorted  *wink2*

 
Quote
.......so valve clearances are the next challenge. .....

 Not hard, just a *bit* timing consuming- depending how you do it, and everyone no doubt has their method, but we'll get to that when you're ready
Title: Re: Iron filings on magnetic sump plug
Post by: morris on 07.05. 2018 07:19
Had a similar issue. It was like a tower of grey fluff building up on the magnetic sump plug.
Using high zinc oil improved matters enormously.
OTH, it could also just be the engine settling down *dunno*
Title: Re: Iron filings on magnetic sump plug
Post by: wortluck on 07.05. 2018 10:36
Yeah, grey fluff describes it well.  May well try the high zinc oil once I've got through my current stocks.  What do you use morris?
Title: Re: Iron filings on magnetic sump plug
Post by: morris on 07.05. 2018 21:35
Penrite classic light 20/60
Title: Re: Iron filings on magnetic sump plug
Post by: wortluck on 07.05. 2018 22:13
Cheers morris.  I've heard Mannol Safari 20/50 is also good?
Title: Re: Iron filings on magnetic sump plug
Post by: ellis on 07.05. 2018 22:21
Yes Penrite classic light 20/60 is a very good oil with a high level of zinc. Just the job for our classic bikes.   *smiley4*

ELLIS