The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Angus on 03.08. 2018 12:29
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1960 A10. It has been running fine, does not get used as much as I would like as my son has custody and uses it infrequently. Was said to wet sump when we bought her 6 year ago, but we have never really had a problem. Had been left for two week and its very hot here straight 40 oil. Anyway he rode her to work about 15 miles and when he got there oil dripped all over the ground from the primary side and rear of the enclosed chain case. He checked the oil tank (not done before departure) and it was empty. He has told me it took 4 or 5 attempts to start it. There is also oil in the left hand exhaust pipe. So even if she wet sumped and blew some oil out I would expect it to stop and return some to the tank. I have not done anything yet as its too hot so will start investigation this evening.
Edit forgot to mention I checked the oil about 4 weeks ago and it was fine only probably done 100 miles since then.
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The valve in the scavenge pipe is jambed in the top of the scavenge tube.
Thus the oil fills up the sump, which makes it really hard to kick.
Then when it gets high enough it leaks down the crankshaft and fill up the primary.
A deceased oil pump ( scavenge side ) will do the same.
Drain the sump & the primary then fill the oil tank, remove the plugs , kick it a few times to clear the cylinder refit the plugs then ride it home.
When you get home do the same.
After that see if a thin pick up magnet can pull the ball back down.
Some times solvent degreaser or carb cleaner squirted up the tube will free it . otherwise it will be out with the pump.
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Got it home I have a big van that seams to have become a breakdown truck *smile*
Drain plug from sump plate removed. About 1.5 litres in the sump (possibly more but lots). A bit more black sludge on the drain plug magnet than usual.
No extra oil in primary case
Left plug clean
Right plug oily Strange as only left exhaust is oily
Sump plate removed, no debris and ball in the correct place in pipe. Trevor did you mean that with the above amount that would cause the ball to jam at the top.
So I am going to put some oil in it turn it over (plugs out) until I get some drip out of the bottom. Sump plate back on and then push around the block to see if any return. If none I ‘may’ try to start it to see if it returns or if the oil just gets lower.
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Hi Angus,
Is the sump plate fitted with the magnetic drain plug near the oil pickup pipe?
I had trouble with a bike where the magnet prevented the ball from being sucked up by the oil pump
It had been fine for quite a while after a rebuild but one day decided to wet sump *conf2*
The plates I got from SRM at the time need to be fitted the "WRONG WAY" to move the plug away from the pickup
John
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Thanks John, not sure of the origin of the sump plate, on the bike when I got it. Not seen similar. The magentic drain plug is an allen headed bolt in the centre, it is forward of the pick pipe and has not caused a problem in 6 years, but who knows. I decided the pub was a better option then starting it as I may sleep after that rather then finding it fills the sump again. I will man up tomorrow and run it to see what happens.
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Possible should not have post this before investigation but after 6 year service and little use in winter she has been pretty reliable (one clutch problem).
Pushed her around this morning nice return, started her up nice return no drop in oil level in tank. Filled her up and rode her 5 miles around town. Good return and no drop in level in the tank. No nasty noise, no smoke all is good with the world *smile*.
It reinforces, that even a bike that does not normally wet sump, you MUST CHECK THE OIL LEVEL just in case.
It appears that a wet sumped bike will not necessarily clear itself as it can stop the return.
I have told my son to always check it from now on, he has taken the Norton today for a change while I build up some mileage on the A10 and ensure that really is it.
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The only time I don't (reluctantly) check the oil return is when I'm leaving in the dark...(I could if I remembered to carry a light)
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Pleased to hear that you got away with it Angus.
On passing on the 'how to live with BSAs' knowledge... my lads often say they want a 'teach in' but then they're always busy. It's got to happen before I hand the bikes over because I don't want them using the forum after making uninformed errors.
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Reusing this thread as its done it again.
Now please don’t laugh, it has taken 3 months for me to finally reassemble the A10 and all I wanted to do was put the last bit of the fully enclosed chain case on (the bit behind the primary inner case). Whilst doing it I purchase a new set of exhaust that did not fit and so today I put the old ones back on just to get the dam thing together. She has a new style sump plate with drain plug so that came out about a month ago as I thought she may have wet sumped about 200ml came out. In the month since less the 50ml in drips. So everything tightened up and after much kicking she started and settled into a nice fast idle. Waited for return nothing, then a flow of oil from underneath from the breather. Took sump drain out and 600ml in there. So there is obviously something wrong with the return again or still. I will do what I did last time and check again which I think was to basically prime the pump and sump by pushing her with plugs out until I get a return. If that works is there anyway without removal to check the pump return. It has always ‘looked’ fine when I have checked it.
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Welcome to the world of BSA A twins and their foibles – including the unreliable oiling system. Recently my GF decided to stop pumping oil. No return and little in the sump. Pulled the t’cover and removed oil pump. Stripped it, could find nothing wrong and so put it back, having injected some oil into the feed side first. No oil flow. Did that five times and then put the bike at the back of the shed. Of all the bikes I’ve owned over the years, the GF has been the most unreliable – by a country mile. Always something quirky, never simple like frame breakage (Velocette) broken cam follower (B31) vibration and gearchange issues (Weslake) big end failure (James 125) etc. Pity, as the A series ride quite well and their handling is second to none.
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angus ive had a similar problem over the winter where the oil turned to sludge and blocked the pick up / return oil circuit. short runs didnt help. after i changed the oil and blew out the oil lines i managed to reverse the oil pipes. i would check those pipes are correct first
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RD, your sample size is 1, same as mine.
My A10 has been excellent to date, not a single problem once some initial fettling was completed.
Which bike is representative of the A10 series as a whole, your problematic bike or my problem free bike?
Glen
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You have my sympathy, Angus and RDfella!
But . . . having done a good 50K on my own current A without any major hassle . . . without wishing to be disagreeable at all, I don't think they are unreliable, I really don't!
Of the bikes I have and have had, the A can be relied upon to do the doings, with low maintenance and ridiculous reliability. In the 12-or-so years I've had this one (think I joined this forum in 2007when I got it), it's had some new crank shims, exhaust valves and guides, cam followers (just because I could get some good ones when the engine was apart for the only time), some rings, oil pump gears - just because, too - and a some on-and-off tlc to the quite-knackered but always-works gearbox. And she still goes first prod, sounds Ok and gets you there. All over France, runs into the UK, into Spain etc etc. It's a crap and 'not-right' bike compared to many on here - but it works and goes on working. Not thrashed often, being a low spec motor, iron head LJ crank & thick flange blah blah, but good for all day at 60mph. Seriously, can't fault it. Handling is almost to Norton standards bar the forks, but the 'get-you-there-and back' factor is right up there. Only punctures, a stripped fibre mag gear, and an encounter with some scrap metal which buggered the rear sprocket on a country lane, have ever stopped it.
I don't know why this one of mine has been so good, I really don't. It was cheap to buy, I had no great expectations. It's not cossetted, in fact it is largely ignored and very seldom cleaned. I've thought of letting it go to folk who've asked (because they see it always works), but have always said 'no'. I owe it more than it owes me. Because it's not at all valuable, far better to keep it than take a modest price and put the ££ towards something 'better' . . . that isn't. I've found that the more I've paid for things over the years, the more trouble I've had, coupled with that ***** off feeling . . .. 'Shiny' is the enemy of function maybe?
As you can tell, I quite like my A!
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angus is it a magnetic sump plug? I don't know what's happening with these bikes that won't pull the oil from the sump because even when I rebuilt mine having well lubed everything I started it up and after 10 to 20 seconds it had oil pushing up the clear pipe to the rockers and back to the oil tank , the only time I had oil out of the breather and into the mag is when a mate called round to go for the first spring run and it had been stood for winter and I was in a hurry to get going. even when I check if its wet sumped after fitting the srm pump [which it doesn't] and leaving the cases empty as soon as its fired up seconds later oil is flying back, does anyone think excess gasket goo in small portions is being washed down and could be the bogy man in these non returning oil problems *dunno2*
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Angus and RD
This was the problem Steverat had with his recent magnificent rebuild. Turned out to be an obstruction downstream of the take off to the rocker feed.
The whole of the scavenge side needs to be examined for obstructions, air leaks, blockages and mechanical failure eg sheared off or failed pump drive. The ball valve in the sump is number one suspect, magnetic sump plugs are a known foible. The trick of a plastic tube in a bowl of oil to observe pick up is simple but messy. Check flow and return hoses, wash out the oil tank, reverse flush the oil return pipe in the tank and blow it through and make sure there is no debris in the system. Air leak between pick up pipe and crankcase is rare but possible.
berger has some sort of aura that allows his bike to run without failure with the oil pipes reversed......must be the drink... so don't do that, and yes, gasket goo, silicone, odd bits of mechanical detritus are all things to look out for.
Good luck to you both.
Swarfy.
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I thought Berger had quite a bit of damage from that reversed pipe run, if I read correctly? Not the total destruction one might expect tho.
Glen
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Did you prime the scavenge pick-up?
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worntorn lots of damage but it kept running on a bit of mist as I found out when I took the prv out and started it, just to see spits of mist and no proper flow. once I realised what I had done I put the pipes correct and put my test gauge into the prv with the relief blocked off and was surprised to see the gauge fly round and the connecting pipe BALLOON! stopped the engine before me and a mate got covered, big end shells took a lot of the pain and not the crank ,and the top end with colisbro guides wasn't hurt at all!!cam and followers toast- left hand barrel gauged by circlip, pistons hammered , cam bushes toast with super wear at the bottom of them of coarse, and what could be described as a rattle pump [oil pump] that still threw a lot of pressure out. this was changed because I didn't trust it with new rebuilt engine but it was still performing outstandingly. I am very lucky not to have been in a complete snotty mess , I was doing 80's mph on duel carriageway *eek*. when I saw what my oil pump could do after it had been beaten up I wonder why these other bikes can't return the oil *conf2* edit I forgot idler bushes not too happy as well. breather cork fed up, and as musky pointed out when I thought I advanced the timing I retarded it which killed everything and had to coast into the side listening to her dying . several fags later after I realised I had cooked it [it was furnace hot!!]I jumped on the kicker and several kicks fired her up and I nursed her home at 30 -40 mph not sounding very happy. unbelievable story I know but over filling the tank helped me get away with it as every now and then on a left hander oil was over the return hole. so what I am getting at is the pump was pulling a bit of oil even after it had been pulling air the same as when it was on the side stand when I did the pressure check and got oil mist but no pressure--- until I put the pipes are calling the right way round! I remember taking the feed off at the engine and nothing was there and thought blockage , then looked twice...… PILLOCK that will never happen again different connections now, thankyou for listening the purse was emptied on the rebuild!!!
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Both my A’s appear reliable normally this is only the 2nd real can not use it problem on the A10 and the A7 has occasional little faults but just needs regular TLC.
I have not touched anything on the timing side so oil pipes etc. are defiantly correct. She has done 400 miles since her last little episode and once she cleared herself of smoke etc has not used any oil or caused any real problem. She has sat for three months which is a long time for one of my bikes, so could be oil turning to sludge and blocking the return. I will remove sump plate like last time check if return appears clear and prime it, then this time I will put a large jug under her with some oil in and a pipe extension from the return pipe into that oil and see what happens.
ps thought I posted this last night :)
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The return pipe extension into a jam jar he been done and the oil disappeared from the jar really quickly and back into the tank. SO I will put her hack together prime the return side and see what happens. Just have to check every time that there is a good return.
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Well that bit is all back together and primed with oil, then a good return to tank. The lesson I think is IF you drain the sump and leave for any length of time make sure you prime the pump with oil before starting. It maybe that the return of the pump is a bit tired but it does not like pumping air. Onto the last job rear brake.
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Oh Bugger, 500 nice joyful miles on multiple rides and then a lake of 'oil' under the bike. I have a theory this time, will report later.
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The saga continues. I know I should have stripped and checked but she rides so nice and good return to the oil tank. So I have been riding and monitoring oil level in tank with marked dip stick and she did not appear to be using or losing any oil with regular riding covering appox 500 miles. Then a two week layup. Started her up and checked oil return all good, left her ticking over whilst getting my riding gear. Upon my return a lake of ‘oil’ underneath her checked and tank still full with good return flow but oil smelt strongly of petrol checked with finger and very thin and more like petrol then oil.
I checked petrol taps and one has a leak into the fuel pipe, quite a rapid dip now fixed with a new cork. Today I drained ‘oil’ 1.5 litres in sump of very thin black liquid, the same stuff in the oil tank. Not much sludge on the magnetic drain plug. I really don’t know how the engine has not blown up in a big way, but she sounded really sweet when sitting there ticking over so smoke or rattles at all.
So my theory, the leaky tap has allowed petrol to get into the engine (I thought the float chamber needle valve should stop that) and fill the sump diluting the oil, the two week layup with the leak and thinned oil have caused an excessive amount of the mixture in the sump which has caused her to pump the stuff out of the breather and all over the ground. It could have been the problem all along.
I think I will get a new viton tip needle value in case of another leak or someone leaving the tap on. I will put some oil in her and kick it through to clean the oil ways of this thin stuff then drain again and try her with fresh oil again.
I need her for a trip to Scotland in the autumn with my VMCC section and my son (I don’t trust the Norton as much yet)
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G'day Angus.
Now change the topic title to "where did all the extra oil come from" *smile*
Yes if used daily the small amount of fuel seeping in will get evaporated out once it all gets hot. 1.25Lt in there could have been catastrophic.
Cheers
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Well I am really not sure what to do. Put a couple of litres of halfords 20/50 classic oil in. Primed the oil system with lots of kicks (plugs out). Started her up good return to tank and no nasty noises that I can hear. Drained sump quite a bit of sludge on the magnetic plug, drain the tank quit a lot of sludge in there to, I had cleaned it before putting new oil in. Anyway refilled with the 20/50 oil, primed and ran her for about 15 miles. She seams to be fine came home and had a careful listen no nasty noises, put her in gear and slipped the clutch to put her under load still nothing noise wise. A little oil underneath her but that could be left over from before. Gave her some quick revs some black smoke but that is petrol (oil is white smoke I believe) and no additional oil underneath.
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I had this problem on a A10, riding one day looked down oil everywhere, brought home and checked everything changed pump cleaned out oil ways the lot could not sort it, then sitting there one night and thought what about pressure release valve dismissed it at first as thought that can not cause it, anyhow in desperation swapped it with a spare and Bingo all fine, makes no sence but it worked