The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: siwilson on 04.06. 2007 23:47

Title: Constant oil leak?
Post by: siwilson on 04.06. 2007 23:47
Hi just discovered this forum, maybe someone can help me?

I know all Beeza's leak some oil, but my '59 A7 seems much worse than most. I don't get to ride it much so unfortunately it spends much of its time not running. Over time it constantly leaks most of its oil out. I first tried fitting a manual oil on/off valve on the feed from the oil tank, but then when I got worried I would one day leave it off by mistake, I fitted the anti-wet sumping external valve that Bri-Tie (and others I believe) supply.

Still masses of oil leaking out.

It's hard to see where it's coming from too. Doesn't appear to be from the sump/filter plate itself.

Any ideas of causes/cures? I just don't understand how the oil gets out of the tank?


Title: Re: Constant oil leak?
Post by: fido on 05.06. 2007 07:17
The usual way to trace such leaks is to clean all the oily crud off the engine and leave it a short time to see where more oil emerges. A lot of bikes allow the oil to seep into the crankcases when stood for a while but most of it usually stays in there.  ;)
Title: Re: Constant oil leak?
Post by: LJ. on 05.06. 2007 09:57

Perhaps this is one of the positive arguments for having a *good thick monograde oil* rather than a thinner type.  *smiley4*
Title: Re: Constant oil leak?
Post by: Brian on 05.06. 2007 10:29
Hi Simon, wet sumping is a common problem with all british bikes but the oil should stay inside the engine as Fido says. If it didnt do it when you had a manual tap fitted in the line but does now with the anti wet sumping device that tells you the anti wet sumping device is either fitted incorrectly or doesnt work. Give the engine a good clean and watch it carefully to see where the oil is leaking out. You can fit a after market sump plate with a drain plug in it, doesnt cure the problem but makes it easier to drain the sump when it happens. Try and ride the bike as often as you can, even if its a small ride around the block. Good luck, Brian.
Title: Re: Constant oil leak?
Post by: siwilson on 05.06. 2007 12:27
That's the strange thing. Even with the manual tap in it leaked.

Perhaps I should try thicker oil - what's the current recommendation? Up until now (I have owned the bike 30 odd years) I have always stuck in 'normal' cheap Halfrauds multigrade.

As much as I'd like to ride it more frequently, that isn't always possible.


Title: Re: Constant oil leak?
Post by: Brian on 05.06. 2007 12:52
If it leaked with the manual tap in the line then the only thing I can think of is that the tap is in the return line instead of the delivery line, is this posible? I am not familiar with the oils you have as I am in Australia. Can someone closer to you help out. I run mine on a 20-50 multigrade oil made by a company called Penrite.
Title: Re: Constant oil leak?
Post by: LJ. on 05.06. 2007 16:59

Ahemm... Looks like the forum might be in for its first 'oil war' as seen so many times on other forums. Well... without upsetting anyone. I use Castrol straight XXL40 and have got on fine with this. Dont get me wrong I have used 20/50 and filter but found my A10 didnt like it. There was always oil blown out of the breather it was a constant mopping up proceedure, Mrs LJ has a very nice expensive flying jacket which was starting to get a bit covered, so a change of oil was needed. I dont know why I had that problem as so many other classic bike owners seem to get on well with the 20/50 & filter set up. Wonder if this is why they are called 'greasers'  ;)
Title: Re: Constant oil leak?
Post by: bsa-bill on 05.06. 2007 22:25

First off "all A10/7s" do not leak.
Mine is oil tight, just built up carefully, very little silicon used and then on one side of a gasket only, nothing used between the crankcases but make sure both sides are very clean.
If this sounds like I'm getting big headed don't worry I did have one leak and it was a big one, turned out I had put a wrong bush in the intermediate pinion ( inner timing case ) flooded the dynamo chain chamber and came out past the dynamo eventually.
Title: Re: Constant oil leak?
Post by: Brian on 05.06. 2007 22:55
All this debate about weather A10's do or dont leak oil and what oil to run is all very well but none of this is helping Simon with his wet sumping problem. Does anyone have any experience with these anti wet sumping valves? Perhaps you could pass on your expierience with them. Personally I dont like the idea of putting anything in the delivery line that has the potential to fail but I am fortunate enough to be able to use my bikes regularly. If you have to store your bike for periods of time as it seems Simon does then wet sumping would be an annoying problem. Lets try and help here rather than get side tracked.
Title: Re: Constant oil leak?
Post by: fido on 06.06. 2007 07:52
It might not be wet sumping though, could just be a leaky oil pipe. *conf*
Title: Re: Constant oil leak?
Post by: Brian on 06.06. 2007 08:23
Good point. The oil may be running down the oil line from before the wet sumping device and down the back of the engine cases. Needs a good clean and a cafefull inspection.
Title: Re: Constant oil leak?
Post by: dpaddock on 06.06. 2007 21:48
fido and Brian might be on the right track. Check the feed pipe connection at the tank, the oil filter/drain joint - and check to see if the tank is leaking; such a leak is not usual but it does happen.

Try this technique for cleaning:
Fit a Hose End Sprayer (Gilmour, US$3 at Wal-Mart, or equivalent) to your garden hose and fill it with a 50/50 mix of water and Simple Green or other biodegradable liquid soap. Connect the hose to hot and cold water taps using a Y-connector, and hose the area with the hottest water you can. The combination of hot water, soap and water velocity does a marvelous job of cleaning. And the area tends to dry quickly afterward. Your laundry room is probably the best source for hot and cold water taps.

Keep us posted, Simon.
Title: Re: Constant oil leak?
Post by: siwilson on 07.06. 2007 19:56
Thanks for all of the suggestions. I will try and give the engine a good clean down and have another close look. I will let you know if I find anything.
Title: Re: Constant oil leak?
Post by: BrianDallasTX on 08.06. 2007 01:08
cracked oil tank perhaps?  I run straight 40 Castrol no problems.
Title: Re: Constant oil leak?
Post by: snowbeard on 03.09. 2007 22:13
I've been looking at these ball valve, anti sump backflow checkvalves, whatever you want to call them.  I've seen a few on eBay for 50-70$, plus shipping, but wouldn't these be generally available at a NAPA?  I guess one would have to get the right spring constant so there was no chance of it not flowing when you wanted it, but I should think someone knows this?

also, I have already concieved of using a manual switch, but linking it to the kill switch so it grounds the magneto when closed, then you could never forget and drive with it locked off?!  (I'll get right on that...)  ;)
Title: Re: Constant oil leak?
Post by: wardleybob on 04.11. 2012 11:20
hy I have a anty drain valve you can have free I onece had one stick never again If my bike is standing for a week or two I simply drain the oil threw a bolt Itaped In the sump
Title: Re: Constant oil leak?
Post by: stu.andrews on 05.11. 2012 12:22
SRM do a sump plate with convenient drain bolt. 5 minutes to drain the excess in the sump & return it to the oil tank.
The previous owner of my A7 had an anti-sumping valve which stuck shut & wrecked the bottom end.
Don't go down that route!
Title: Re: Constant oil leak?
Post by: cyclobutch on 05.11. 2012 15:27
Folks - I think maybe Wardleybob has opened up some historic train of thought here. I'd hope the original issue has long since been addressed.
Title: Re: Constant oil leak?
Post by: wilko on 05.11. 2012 22:07
And please, no one starts going on about oil thickness! Once your oil is hot it will leak just the same.
Title: Re: Constant oil leak?
Post by: BSA_54A10 on 06.11. 2012 06:30
Wash your bike thoroughly then dry it.
Spray some WD 40 all around the oil tank, oil lines and sump.
While still wet liberally dust the wet WD 40 with talcum powder ( I won'r recommend concrete dust again although it is better ).
Come back a week latter and the origins of the oil leak will be most obvious
Title: Re: Constant oil leak?
Post by: duTch on 06.11. 2012 09:31

Good one Trev, means my Concreting days are over
Title: Re: Constant oil leak?
Post by: shuswapkev on 06.11. 2012 22:51

 for oil sealing... i have stopped using paper gaskets...surfaced all joining surfaces on a cast iron table...recessed the threads (they always seem to stick out a bit)..and assembled with loctite 518...similar to yamabond...and..the oil stays .. inside.. loctite 518 makes taking apart very easy...just looks like candle wax... i was using the paper bits..but whether they were in or not in didn,t make any bother...this is on a 69 a65... 50 matchless g/80...  46 b31...and a 76 e-glide...95 posty bike..and a bunch of other real good... the loctite goo costs way too much...but lasts forever...well...a long time...
 the only with no oil blowing out...i live in queensland, a few miles from a surf the problem of creeping rust...
but i have solved that too.... i spray or wipe some oil over the bare iron bits... ...

the only thing i use siliy con on is tin primarys...cut a bit of melamine to fit neat inside the outer...then wipe contact areas on melamine with grease... get some better quality silly con... from a commercial glass place...not a builders yard.. there is a big difference...and it costs more... then grease up both sides of the tin cover...screw together..melamine in morn you will have 2 flat  smooth surfaces.. mine will hold oil for months... some does ecape..think thru the drive hole...