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Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: owain on 18.09. 2019 08:48

Title: Engine failure troubleshooting
Post by: owain on 18.09. 2019 08:48
My A10 has been running well for the last few months and I've managed to put a lot of miles onto the newly built engine. However, yesterday it broke down on me in North Wales. To make matters worse it was whilst being filmed by ITV for a TV segment ;D. I ended up having to get my A10 loaded in the van and taken home.

Today I'm going to try and repair it but of course wondered whether anyone could shed some light on the symptoms to find the cause of the problem. In brief, I first started to notice the engine fluttering (i.e. not combusting) at when in top gear and at speed. I pulled over and checked the carb, they looked pretty good, albeit a perhaps a tiny bit too lean. Set off again. A few minutes later the motorcycle started fluttering but now at mid-speed (30-45mph). Dropped the speed and kept riding a little a few minutes longer but then the motorcycle fluttered and stopped combusting entirely. I pulled over, Tickled the carb until the float is flooded, engine starts straight away. Ride 800yds. Engine flutters and stops. Tickled the carb again, engine starts, ride another 800yds and repeat again.

My initial thought was that the engine is using fuel at a faster pace than it is replacing. So I knocked on a campsite receptions door and asked to borrow a socket set to remove the tank and get to the carb. I removed the carb it's float bowl, the main-jet holder had vibrated loose, so I tightened it back up, thinking I had found the problem but had the same symptoms. Eventually the distances I could travel after tickling the carb reduced more and more (600yds, then 400yds, then 200yds) until the engine wouldn't start at all.

Does anyone have any ideas about the possible cause of this problem? Thanks guys!
Title: Re: Engine failure troubleshooting
Post by: duTch on 18.09. 2019 09:07

 
Quote
...... I pulled over and checked the carbs, they looked pretty good, albeit a perhaps a tiny bit too lean.........

 
Quote
......... I pulled over, Tickled the carb until the float is flooded, engine starts straight away. Ride 800yds. Engine flutters and stops. Tickled the carb again, engine starts, ride another 800yds and repeat again.........

 How many carbs do you have, one, two or two into one *conf2* ?- I suspect  the first ^^quote^^ means two S-plugs....The first think that comes to mind is a blocked vent in the tank cap, and next that you're low on fuel or crap in the fuel lines/tank filter....other than that requires thought *dunno*
Title: Re: Engine failure troubleshooting
Post by: owain on 18.09. 2019 09:20
Possibly. I did remove the fuel cap to see if that remedied the problem whilst riding but no luck. Fuel lines also appear clear i.e. if I detached one and open the opposite fuel tap, petrol comes running out of the fuel lines. I'll give it a look...I'll also edit my grammar haha

I should also mention that I recently modified the exhaust with a mute, that would certainly increase exhaust back pressure but it's been running fine with it on for a week or so before this incident.
Title: Re: Engine failure troubleshooting
Post by: Swarfcut on 18.09. 2019 09:28
Ha....The curse of the A10 strikes again, frustrating your chance of stardom.

Ok, duTch is on the money here, anything that stops that fuel vapour getting to the inlet manifold is suspect, from a blocked tank breather, to a blocked main jet and anything in between. So start with the easy stuff, fuel taps, tank filters, float, needle. Establish fuel is getting to the carb, then move on to jets, internal drillings, sealing washers, correct assembly, air leaks. Good chance its the tank, recent enthusiastic riding has shaken up some sediment....taking the fuel taps out may reveal all! A couple of cheap in line fuel filters are worth fitting, and give visible indication of fuel supply.

Swarfy.















Title: Re: Engine failure troubleshooting
Post by: Greybeard on 18.09. 2019 09:29
I once had a blocked tank cap vent. I was able to drive for a couple of k before the engine stopped. After a bit of fiddling the engine would start again and off I'd go for another short run. Rinse and repeat!
Title: Re: Engine failure troubleshooting
Post by: Klaus on 18.09. 2019 09:58
There is also a gacefilter in the top of the floatbowl, may be the is some dirt.

cheers Klaus
Title: Re: Engine failure troubleshooting
Post by: Greybeard on 18.09. 2019 10:16
Has the magneto been serviced? A faulty condenser tends to fail when the bike is hot.
Title: Re: Engine failure troubleshooting
Post by: bsa-bill on 18.09. 2019 10:27
try both taps turned on - might show or eliminate something
Title: Re: Engine failure troubleshooting
Post by: ironhead on 18.09. 2019 10:28
I'll put my money on Klaus's suggestion.
Title: Re: Engine failure troubleshooting
Post by: owain on 18.09. 2019 12:02
Righto, I just tried starting the bike before reading all these comments and the damn thing caught fire! Looked like it started at the carburettor. Fortunately it was a very small fire and I had a fire extinguisher within arms length of me, so it was out within a few seconds.
Just how I like start to the morning *lol*

I've cleaned it up now and I've just removed the carb. I'll drain the tank and remove the petrol taps. I also noticed that air is escaping from the timing side cover via one of the screws when I kick it over...not sure if it is note worthy how the bike is? I'll check back on the forum regularly throughout the day to keep you updated and see how things progress!

Also to answer Greybeard, Yep the magneto has been serviced by APL magnetos a few months ago. I'd be hugely disappointed if the mag is playing up already.

Image is from post-fire extinguisher antics:
Title: Re: Engine failure troubleshooting
Post by: Swarfcut on 18.09. 2019 12:53
A fire is perhaps an indication of another fault. Sure it was the carb? A petrol soaked magneto is an obvious a fire source, but for a carb to light up means it has fired and spat back through the inlet manifold.  If a compression check and tappet clearances are OK, meaning the valves are sealing, could be the ignition timing is out, and it fired while the inlet valves were slightly open....or the valve timing has moved, key on camshaft sheared and cam no longer correctly timed, but here ignition will stay correctly timed to the crank. Unlikely scenarios, but something to bear in mind.

Swarfy.
Title: Re: Engine failure troubleshooting
Post by: Flashgreubon on 18.09. 2019 13:28
Just to remind you that there are a lot of faulty soft mag brushes around that wear to nothing in no time!
Title: Re: Engine failure troubleshooting
Post by: owain on 18.09. 2019 13:29
Thanks Swarfy, perhaps I need to recheck the tappet clearances again since rebuilding the engine. I haven't got my compression test kit with me at the moment, just a toolbox with the basics. The only compression test I've done is placing a thumb on the spark plug hole. Very rough test. I've removed the point assembly to give the points a quick clean and lost the little rubber grommet that sat between the metal arm and the points lever. Is this just to keep the lever in place i.e. I can replace it with any piece of non-conductive material?

An update on checking the fuel lines though. I've taken the carb to bits. Jets are clear but the tube that accommodates the float needle had a small piece of material in there. Not sure if it was large enough to cause a stoppage but then again anything where it shouldn't be isn't helpful. There was some a few rust particles from trapped behind the gauze filter in the carb. I removed the petrol taps and they both seemed pretty. I gave everything a clean and will removed any bits. I'm off to B&Q to get some clear tube to replace my fuel lines which look like they could crack at any moment.
Title: Re: Engine failure troubleshooting
Post by: Swarfcut on 18.09. 2019 13:50
Thanks Flash... Carbon clogging up the slip ring will fire both plugs at the same time if the HT is strong enough to track around the slip ring, so a nice clean  and a check on those brushes will eliminate another potential cause. Could account for the spitting back.

 Any insulating material  shaped to size will do in the short term to replace the missing tit.

Swarfy
Title: Re: Engine failure troubleshooting
Post by: mugwump on 18.09. 2019 15:55
Not too sure that B&Q sell ethanol proof fuel line though! If that starts to disintegrate then you will have blocked jets etc.
Title: Re: Engine failure troubleshooting
Post by: Greybeard on 18.09. 2019 16:25
Not too sure that B&Q sell ethanol proof fuel line though! If that starts to disintegrate then you will have blocked jets etc.
Maybe for mowers?
Title: Re: Engine failure troubleshooting
Post by: owain on 18.09. 2019 16:47
Update: fitted some clear plastic tubing for the fuel lines to the carb. So I bought some from the local hardware store in N.Wales (Stermat). No idea if it is ethanol proof or not. So I've just reserved some 6mm fuel tubing from Halfords.

I cleaned all the carb components and blew through the jets with some hose to make sure they were clear and reattached the carb.

I also checked tappet clearance, all of them were very tight. Opened them all up some that a 0.015" feeler gauge could slide between them smoothly.

Kicked the bike and started the engine ticked over nicely. I'll take it for a test ride once I've refitted the fuel hose with hose that is definitely fuel proof. I can see straight away however that the left fuel tap (which doesn't have a filter attached to it) allows bits of debris to pass to the carb i.e. this debris can be seen in the clear tubing. The fuel tap on the right has a filter and the fuel looks nice and clean. Just so happens that I usually ride with just the right fuel tape open and the left (non-filtered) tap closed....except when the TV crew were filming, then I had both taps open and the bike conked out after an hour or so of riding.

PS: I'll also fit an extra filter in the lines.
Title: Re: Engine failure troubleshooting
Post by: Greybeard on 18.09. 2019 16:51
Update: fitted some clear plastic tubing for the fuel lines to the carb. So I bought some from the local hardware store in N.Wales (Stermat). No idea if it is ethanol proof or not. So I've just reserved some 6mm fuel tubing from Halfords.

I cleaned all the carb components and blew through the jets with some hose to make sure they were clear and reattached the carb.

I also checked tappet clearance, all of them were very tight. Opened them all up some that a 0.015" feeler gauge could slide between them smoothly.

Kicked the bike and started the engine ticked over nicely. I'll take it for a test ride once I've refitted the fuel hose with hose that is definitely fuel proof. I can see straight away however that the left fuel tap (which doesn't have a filter attached to it) allows bits of debris to pass to the carb i.e. this debris can be seen in the clear tubing. The fuel tap on the right has a filter and the fuel looks nice and clean. Just so happens that I usually ride with just the right fuel tape open and the left (non-filtered) tap closed....except when the TV crew were filming, then I had both taps open and the bike conked out after an hour or so of riding.

PS: I'll also fit an extra filter in the lines.
Title: Re: Engine failure troubleshooting
Post by: Swarfcut on 18.09. 2019 19:30
Maybe I feared the worst ,but get that slip ring clean 'cos catching fire is not an optional extra.

Swarfy.
Title: Re: Engine failure troubleshooting
Post by: Peter in Aus on 19.09. 2019 01:57
Righto, I just tried starting the bike before reading all these comments and the damn thing caught fire! Looked like it started at the carburettor. Fortunately it was a very small fire and I had a fire extinguisher within arms length of me, so it was out within a few seconds.
Just how I like start to the morning *lol*

I've cleaned it up now and I've just removed the carb. I'll drain the tank and remove the petrol taps. I also noticed that air is escaping from the timing side cover via one of the screws when I kick it over...not sure if it is note worthy how the bike is? I'll check back on the forum regularly throughout the day to keep you updated and see how things progress!

Also to answer Greybeard, Yep the magneto has been serviced by APL magnetos a few months ago. I'd be hugely disappointed if the mag is playing up already.

Image is from post-fire extinguisher antics:

I noticed in your photo that you don't have a carby drip  tray 67-0120 fitted, without that it is a potentially a fire hazed.   
Title: Re: Engine failure troubleshooting
Post by: ironhead on 19.09. 2019 03:52
Righto, I just tried starting the bike before reading all these comments and the damn thing caught fire! Looked like it started at the carburettor. Fortunately it was a very small fire and I had a fire extinguisher within arms length of me, so it was out within a few seconds.
Just how I like start to the morning *lol*

I've cleaned it up now and I've just removed the carb. I'll drain the tank and remove the petrol taps. I also noticed that air is escaping from the timing side cover via one of the screws when I kick it over...not sure if it is note worthy how the bike is? I'll check back on the forum regularly throughout the day to keep you updated and see how things progress!

Also to answer Greybeard, Yep the magneto has been serviced by APL magnetos a few months ago. I'd be hugely disappointed if the mag is playing up already.

Image is from post-fire extinguisher antics:

I noticed in your photo that you don't have a carby drip  tray 67-0120 fitted, without that it is a potentially a fire hazed.   

Yep, the cause of many flaming A10's
Title: Re: Engine failure troubleshooting
Post by: owain on 19.09. 2019 07:44
Slipring is all cleaned up now Swarfy. Don't want repeats on the road, even if the fire extinguisher lives inside the sidecar!

Good point, I took the drip tray of because it was just so fiddley when trying to squeeze a concentric carb inside. I'll definitely be refitting it as soon as I'm back in my garage!
Title: Re: Engine failure troubleshooting
Post by: owain on 19.09. 2019 19:59
Update: I took the bike for a test ride today after cleaning out the carb, cleaning the slip-ring and readjusting the tappet clearance. It was still fluttering and stalling after a minute of riding. Tickled the carb, engine started and I rode it again. This time the moment the engine stopped; I turned the petrol taps off and drained the float bowl to see how much petrol was in in the float bowl at the moment the engine stalls. There was hardly any.

Took the carb apart again and adjusted the float. Started it up and rode it a good coupe of miles without any problems.

Another question I do have however is about a mystery leak. I've finally sealed the chaincase and confident that it's pretty oil tight but there is a lot of oil travelling down the backside of the chaincase (i.e. behind the clutch) I'm not sure where it's coming from but it's a decent amount of oil dripping. No signs of a leak at the cylinder base gasket. I'm pretty sure I saw someone mention a breather hole somewhere at the rear of the crankcase?
Title: Re: Engine failure troubleshooting
Post by: BigJim on 19.09. 2019 21:20
I would suspect that the two main sources for that oil are the chaincase where the gearbox shaft enters or the engine breather. the engine breather is easily felt with a finger from above to see if that is the primary source. There will be photos somewhere here. lots of opinions re causes and am still working with mine whilst continuing to ride. The chaincase leak is common and lots of opinions on treatment are in those threads. The main thing is the volume and any obvious change from normal (?!).
Title: Re: Engine failure troubleshooting
Post by: muskrat on 19.09. 2019 21:32
G'day Owain.
You must have one of those new "stay up" floats, good. The correct fuel height in the bowl is crucial to tuning. The correct level is 0.090" to 0.120" below the bowl/body joint face. I have a bowl plug with a clear tube to hold up the side of the carb to check.
Yes the breather exits the c/case  back there. Or it could be the mainshaft seal (felt) behind the clutch.
Cheers
Jim types faster
Title: Re: Engine failure troubleshooting
Post by: Greybeard on 19.09. 2019 22:19
Owain,
Can you tell if the leak is gearbox or primary case type oil? In my bike the primary has red ATF fluid, that turns brown after a few miles. The gearbox has EP90, which has a distinctive smell and is, of course thicker than ATF.
Title: Re: Engine failure troubleshooting
Post by: berger on 19.09. 2019 23:36
I have not been to the pub. greybeard have you got any glitter in your box *eek* *whistle* as I understand things EP90 can attack the bushes . I found glitter in my box *eek* when I used to use EP 90.
Title: Re: Engine failure troubleshooting
Post by: Swarfcut on 20.09. 2019 08:31
Owain, The good news is that it's a runner again, but as always another obscure facet of the design appears, to keep you on your toes. On your plunger design, the original primary case seal behind the clutch is little more than a compressed fabric ring, and is a prime source of leakage. The later S/A set up has the felt ring (and sliding plate). The original type seal swaps easily with a modern seal of the same size...shaft, housing, width.

 On the plunger design this seal can only be changed with the gearbox removed from the engine unit, and as you know this ain't a 5 minute job.

The breather exits the engine just under the chainguard extension on the back of the primary case. It may have an extension pipe, if still original, leading down and clamped adjacent to the sump plate.  The gearbox oilseal on the sprocket is another common source of leak, also the mainshaft/drive sleeve bushes.

 So its time to get out the big mirror and the rags, clean off as much muck as you can and observe where fresh oil appears. In the short term, if it turns out to be that pesky seal, try reducing the amount of oil in the primary case. My trick is to drain the case, start the engine, the add oil until a reasonable amount of oil can be seen flicking past the filler hole, rather than a cascade. This shows the chain is just dipping in the oil, rather than deeply immersed. This level helps keep oil off the clutch.

Plenty on the Forum recently about the seal, and how folks have solved the problems of holding it in place. Worth checking gearbox oil, in case that is overfilled and working its way out.

 Looks as if you have a concentric carb fitted, if I have followed your posts correctly.

 Bergs...I can't make up my mind about EP90 and phosphor bronze bushes. Anyone know for sure if this is true or an urban myth? Glitter is more likely to be particles worn from gear teeth in use rather than stuff eroded by some chemical reaction between bronze and oil additives, to my simple mind.

 Swarfy.
Title: Re: Engine failure troubleshooting
Post by: Greybeard on 20.09. 2019 09:01
I have not been to the pub. greybeard have you got any glitter in your box *eek* *whistle* as I understand things EP90 can attack the bushes . I found glitter in my box *eek* when I used to use EP 90.
I am not aware of particles in the gearbox oil. When I had the gearbox rebuilt by an expert last year he said nothing about oils, so I guess he didn't find evidence of bushes being damaged by EP90.
Title: Re: Engine failure troubleshooting
Post by: berger on 20.09. 2019 11:34
ok chaps we will not  *fight* but as I understand these things EP/ extreme pressure oils attack bronze materials because of their additives.
Title: Re: Engine failure troubleshooting
Post by: mugwump on 20.09. 2019 20:50
An obvious question, but what do modern gear boxes use for bushing i/l of bronze.
Title: Re: Engine failure troubleshooting
Post by: RDfella on 20.09. 2019 21:20
needle rollers and the like.
Title: Re: Engine failure troubleshooting
Post by: berger on 20.09. 2019 21:29
modern gearboxes will have a different composition of bronze or brass and possibly use different 90 oils. the old BSA etc bushes have been known to have the copper content in the bushes  react with the EP grade oils firstly causing a type of dark shadow in the bush- sulphide- I think ,leading to the bush starting to wear faster than with a non EP oil causing fine glitter in the oil and in very warm hard working boxes failure of the bush
Title: Re: Engine failure troubleshooting
Post by: chaterlea25 on 20.09. 2019 22:05
Hi All,
There are books written (I'm sure) on how/why some gear oils attack bronze bushes  *eek*
As far as I know (very little) about oil it had to do with "Sulphur" additives in Hypoy oils ????
Some years ago I was given some "gear oil" and I  put it in the rebuild gearbox on my SR
A while later I just before a trip I checked the gear oil level to find "gold dust" in the oil  *eek*
A panic rebuild ensued completed just in time to catch the Ferry *work* *work* *work*

John
Title: Re: Engine failure troubleshooting
Post by: berger on 20.09. 2019 23:16
thankyou john it is the additives that attack and cause corrosion in the bushes with some oils --- Extreme Pressure oils and bronze = sulphide.  I ran EP 90 in my box for ages and when looking closely on an oil change on a nice sunny afternoon I saw loads of small pretty glitter. when I took the box off and put petrol in it and shook it and drained it LOADS of glittery bits came out. I stripped the box and found badly worn bushes. this is why I keep away from EP 90 and use straight 50 in the box
Title: Re: Engine failure troubleshooting
Post by: Greybeard on 20.09. 2019 23:18
Just to check, I will drain my gearbox to make sure.
Title: Re: Engine failure troubleshooting
Post by: JulianS on 21.09. 2019 11:45
Earlier this year, following some gearchange problems, I found the bush in the first gear pinion to be very badly worn. Oil looked quite contaminated with some gold colouring.

Had been using an EP oil. 

It is a needle roller box, no signs of wear on the other bushes in the sleeve gear.

Now using a Morris Lubricants non EP gear oil. Worth considering.

https://www.morrislubricants.co.uk/products/classsteam/classic-gear-oils/golden-film-ag90-classic-gear-oil.html
Title: Re: Engine failure troubleshooting
Post by: berger on 21.09. 2019 12:00
JulianS sort of nail on the head, gold colouring is what I found  when I drained mine ,then after shaking the box with petrol in it larger bits came out. I see the oil thread you put up states NO Extreme Pressure additives, these are what cause the problem. my sleeve gears were affected but nowhere near as much as the layshaft that have a lot more contact with the oil
Title: Re: Engine failure troubleshooting
Post by: RDfella on 21.09. 2019 14:27
Interesting thread. Old Ferguson tractors have lots of bronze in the gearbox / hydraulic system and we were warned decades ago not to use certain oils as they attacked the bronze. And so I didn’t, nor did I ever use those oils in my motorcycle gearboxes. Yet not so long ago on this forum, some were expounding the virtues of gear oil and chiding us for not using it in our motorcycle gearboxes, almost suggesting those of us who follow makers recommendation and use engine oil were some sort of retard. Where are these guys now?
Title: Re: Engine failure troubleshooting
Post by: chaterlea25 on 21.09. 2019 19:34
Hi All
RD,
I have for the last 40 odd years used whatever gear oil that came to hand in my bikes gearboxes
The only time I have ever seen trouble was with the "free"  *sad2* gear oil
Over the winter I will need to go through the gearbox again sometimes it will jump out of third gear under high load
also the 3rd gear whine is getting louder *problem*
I am considering either fitting a splined mainshaft and home brewed Suzuki based clutch or a belt drive
The downside of the belt drive is that it would not allow the fitting of an electric starter
Joint pain has kept me from using the SR very much in recent times  *sad2*

John
Title: Re: Engine failure troubleshooting
Post by: ironhead on 21.09. 2019 23:38
I use Penrite premium mineral 80w90. used for all  gearboxes, diffs limited slip. Goes in blue & comes out blue.
Double checked on the label after reading this thread & says" compatible with copper alloy components".
Been running it in a B33 for over 5 years in constant use with no change in performance.
Title: Re: Engine failure troubleshooting
Post by: duTch on 22.09. 2019 01:00
 As this thread is about Owains' engine problem which seems to be on the way to resolve  *good3*, I'll comment about my gearbox oil in a new 'Gearbox Oil' thread that Big Jim started....;

 https://www.a7a10.net/forum/index.php?topic=14648.0;topicseen (https://www.a7a10.net/forum/index.php?topic=14648.0;topicseen)
Title: Re: Engine failure troubleshooting
Post by: Daveh67 on 22.09. 2019 09:13
Interesting thread. Old Ferguson tractors have lots of bronze in the gearbox / hydraulic system and we were warned decades ago not to use certain oils as they attacked the bronze. And so I didn’t, nor did I ever use those oils in my motorcycle gearboxes. Yet not so long ago on this forum, some were expounding the virtues of gear oil and chiding us for not using it in our motorcycle gearboxes, almost suggesting those of us who follow makers recommendation and use engine oil were some sort of retard. Where are these guys now?
your quote on ferguson tractors is correct, i see many failures due to people using modern 15w40 engine oils in tea20 ferguson tractors.
the oil question will be my next task as my rebuild is coming along well. tinware is primed, engine barrels machined,  working on the sludge trap and timing bush now.
only have pistons plus small end bushes to order now. some chrome and zinc plating and i will be happily tinkering away.
new valves, guides and springs are on the bench. im not doing a 100mph rebuild but im a fussy old bugger and like things to be done right.
ive tried posting pictures but they are too big to post! need to get a teenager to fix that,
my rebuild will slow down for a while as harvest time is near and i will be burning the midnight oil keeping machinery moving.

dave
Title: Re: Engine failure troubleshooting
Post by: BSA_54A10 on 23.09. 2019 14:41
Interesting thread. Old Ferguson tractors have lots of bronze in the gearbox / hydraulic system and we were warned decades ago not to use certain oils as they attacked the bronze. And so I didn’t, nor did I ever use those oils in my motorcycle gearboxes. Yet not so long ago on this forum, some were expounding the virtues of gear oil and chiding us for not using it in our motorcycle gearboxes, almost suggesting those of us who follow makers recommendation and use engine oil were some sort of retard. Where are these guys now?

When syncromesh gearboxes became the nom the composition of gear oils was changed and truck gear oils separated from car gear oils as trucks used to have crash boxes.
For the following 20 years oils were marked "Syncro safe if they did not contain sulphur.
The sulphur was by & large replaced with zinc same as in engine oils.
Eventually when every car had a syncromesh gear box all car gear oils were syncro safe so that was dropped from the lable.
For those who do not know syncro cones are sintered brass
Thus almost every CAR gear oil will be fine in your BSA box
Some truck gear oils will be a problem .