Mayonnaise

Maestro, SEI-V
MickeyMoto
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Re: Mayonnaise

Post by MickeyMoto »

Do you have the baffles in the crankcase breather tube? If you have the breather box these are not present. Well, not on my bike, anyway.
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Ming
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Re: Mayonnaise

Post by Ming »

I always thought that the collector box was basically to satisfy the Californian demands.
I've only seen one on a New York, all the Morinis I have (or had) had their breather pipes routed to atmosphere by various convenient routes.
Maybe this is down to their age and the modifications of previous owners? Whatever, I have never had a mayonnaise problem (except when adding too much oil to the yolk :wink: ).
Papa Lazarou
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Re: Mayonnaise

Post by Papa Lazarou »

This is weird-there has to be a source of water somewhere. Condensation should have gone by now.
'It must be a .....'
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Re: Mayonnaise

Post by 'It must be a .....' »

Hi, On UK 500s the air box is plugged and the original length pipes are left in place under the tank and open to the atmosphere.
I’ve always changed them to longer pipes routed to the rear chain near the front sprocket, but others have routed them to the rear mudguard or to a plastic bottle etc.
I don’t know if it makes a difference but the rocker cover pipes got to the nearside of the collector box and the offside pair link to the air box/or atmosphere. The larger lower pipe has no baffle yet there should be small metal baffles it the rocker covers.
Hope this helps and you solve it soon.
penman
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Re: Mayonnaise

Post by penman »

Thanks for all the replies and suggestions.

I took the collector box off again this morning and as before, it was pretty well full of thick white emulsion - between your fingers it feels like grease, but if you blow it out onto paper (I mean that absorbent blue workshop paper, does it have a name?) - on the paper is is clear that it has a high water content. The breather tubes were also full of it, but if you hold them vertically, water drips out. So, I think this IS an emulsion, which does gradually separate back to oil and water, given enough time.

I cleaned all that out yet again and I also changed the oil for the 3rd time. The oil had done about 170 miles and was fairly murky - in fact I think there was water in the oil, in the form of an emulsion.

There was no mayonnaise in the rocker boxes this time, but the bike had only done 80 miles since the last clean out - I now think the emulsion is forming in the breather tubes or the collector box or both and previously it had only reached the rocker boxes once the tubes were full of it.

Having cleaned it all out this morning and changed the oil - this time using Miller 20/50 semi synthetic - I put another 80 miles on the bike and now once again, everything is full of white emulsion. Maybe a little less this time, but still a LOT! The water has to be coming from somewhere and all I can think of is combustion gasses getting into the crankcase. The compressions were both identical at 205psi - can anyone tell me if that is normal? It sounds plenty to me, but I'm not used to such high compressions! But blow-by doesn't sound likely to me. Similarly a leaking head gasket would make one compression lower than the other and it surely wouldn't run well. I think that leaves a leaking exhaust valve guide as a possibility - do they tend to wear? The bike has done 29,000km. Any other ideas? And please shoot my thinking down, I would be delighted to be wrong. I really can't ignore this white stuff forming at this rate and I need to get to the bottom of it. I've re-checked on my 350 K2 and there isn't a trace of emulsion anywhere, so there is definitely something wrong with the 500. Sadly on this occasion, an Italian tune-up wasn't the answer!
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72degrees
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Re: Mayonnaise

Post by 72degrees »

The guides do wear. But running with a head that NLM said the guides were toast (far too much side play) on, I never got mayonnaise.
Could bad oil control rings still give a reasonable compression test result?
How long had this engine stood unused? I know you cleaned the sludge out with paraffin/air spray but could some sludge/moisture still be lurking, trapped by the crankcase internal webs? After seven year under a bench some of the bearings were beginning to rust on the 350 engine I've just rebuilt - though one head wasn't fastened on properly and the inlet and exhaust ports hadn't been plugged with oily rags, as I did on the 375 when it stood over this winter with no carbs or exhaust system. You would think that any moisture left would clear after several Italian Tune-ups though. I vaguely remember one owner in the early days deciding to sell their Morini when they discovered rust on the dip-stick, but it could be an apocryphal tale!

It's a mystery.
penman
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Re: Mayonnaise

Post by penman »

I think the bike had been standing unused for about 20 years. The starter drive chain was broken and the alternator was open circuit - and of course the carbs had dried varnish and so on. There was a sticker under one of the side covers saying that the oil had been changed at a mileage about 100km before the reading on the speedo - in 1997.

Yes, my original assumption was that some water had got in and was hiding in the sludge, but after 3 oil changes I am finding it hard to convince myself that there is any left in there. I agree that my air/paraffin blasting may have missed some nooks and crannies, but I did put the bore scope in and you can see quite a long way round into the gearbox area and it all appeared to be clean.

Not sure about oil control rings. It doesn't smoke and doesn't seem to be using oil. Hard to tell though with all these oil changes!

I'm not too happy about the valve guide theory either. I have experience of a few Triumph engines, which wear their guides out in less than 20,000 miles and they never make mayonnaise - plenty of rattling noises but no mayonnaise! Of course the breathing and the lubrication is completely different.

To follow the rusty dipstick story of 72degrees, I had a Trident for several years and when I stripped it for the inevitable valve guide job, the crankshaft webs were red rusty - it must have happened before I got it because it was all covered in oil now. Presumably it had spent a considerable time standing, and in damp conditions. The bearings were fine and the bores were fine. It never really gave me any trouble.
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Ming
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Re: Mayonnaise

Post by Ming »

penman wrote:... I agree that my air/paraffin blasting may have missed some nooks and crannies, but I did put the bore scope in and you can see quite a long way round into the gearbox area and it all appeared to be clean...
Just a thought - could it be coming from the traces of paraffin left inside after your cleaning?
Papa Lazarou
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Re: Mayonnaise

Post by Papa Lazarou »

Ming wrote:
penman wrote:... I agree that my air/paraffin blasting may have missed some nooks and crannies, but I did put the bore scope in and you can see quite a long way round into the gearbox area and it all appeared to be clean...
Just a thought - could it be coming from the traces of paraffin left inside after your cleaning?
It would need to be a lot of paraffin. There has to be quite a big source of water for this to be still a problem.
penman
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Re: Mayonnaise

Post by penman »

I did wonder about the paraffi myself, but I've used this method before on various bikes, including the 350 Morini and it hasn't caused a problem before. Besides, I've done 3 oil changes since the paraffin was in there!

With the fairly large hole for the oil strainer, you can get a pretty good view of the main crankcase, and it drains very well, there are no places where anything can sit in a pool. That may not be true of the gearbox area, which you can't see, except with the bore scope, and even then it needs a lot of careful bending to get it round the "corner". All the same, even if that area had a lot of water in it, I think it would have gone by now.

I have a bike club event next weekend which will involve a few hundred miles of riding. I did intend to go on the Bonneville, the "safe option" but I am wondering about taking the Morini instead. If that doesn't dry it out, then it's definitely making its own water. At the same time, I don't want it to let me down on the roadside!
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72degrees
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Re: Mayonnaise

Post by 72degrees »

case.jpg
case.jpg (18.86 KiB) Viewed 20384 times
A reprise of my rebuild before photo so those that haven't seen the innards of a neglected engine can see the full horror.

I agree that whilst gunge could pool in the webs immediately below the crank your spray technique should have reached it and after three oil changes it should have dissipated by now.

Have you tried short circuiting the collector box (using labyrinth baffles in the main breather) and a catch bottle?
The configuration it arrived in does suggest the previous owner may have experienced crankcase pressurisation issues.

Any chance there is moisture lurking in the air cleaner housing - though that shouldn't reach the crankcase unless there is significant blow by.

A link to a thread on a Norton forum which might depress you:
http://www.accessnorton.com/excessive-m ... 42-60.html

"Update on the sludge maker. New std rings in slightly worn bores. No honing, just a deglaze of sorts. 350 miles now and 1 teaspoon of water only in the catch bottle. Yes there is some 'mayo' in the breather and tank but not like before and this is in low temps, around 40-50F."

A very different lubrication system (dry sump and oil tank) though, so prone to foaming and probably not relevant to Morini wet sump unit construction setups.

Give it the long ride treatment. I doubt it will fail. Though it might be worth taking measures to ensure the mayonnaise doesn't get in to the air filter, or on to the back tyre. I ran a clapped out Vauxhall Cavalier for a couple of thousand of miles that blew oil out of the breather like the Torrey Canyon. I ended up routing the breather in to an empty 5 litre oil container (vented to atmosphere) and returning the 'distillations' to the engine. It's life was terminal for other reasons and it just wasn't worth having a rebuild or exchange engine and saved a significant amount on buying oil to keep it replenished. Still went surprisingly well.
penman
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Re: Mayonnaise

Post by penman »

72degrees - thank you for all that. As you say, the Norton thread does make depressing reading, and it sounds as if his problem wasn't really properly solved. My Bonneville, which does have a similar oil system to the Norton, doesn't make any mayonnaise and the oil stays pretty clean. That's a US model and the breather is routed into the airbox, but there's no evidence that anything comes out of the breather. It all points to some issue with the Morini which is leading to combustion gases getting into the crankcase. There aren't that many possibilities, but I think they all mean a top end strip-down - and after all this sludgy oil, I think I'd like to look at the sludge trap. I'm not too keen to ride it far like this because the oil is going sludgy in just a couple of hundred miles and that can't be good.

When I put it together, the air cleaner was clean and dry and I put new filters in there. A week or so ago when I first noticed this problem, there were lumps of mayonnaise in the air cleaner and the filters were wet. Of course I cleaned and dried it out but within a few miles I could see water droplets in the transparent breather tubes and the white emulsion was creeping up from the collector box. Yes I could try venting the crankcase to air, via a labyrinth breather, I do have one, but I'm not sure I see the point, it shouldn't be doing this. As I've mentioned, my 350 has exactly the same breathing system and it produces absolutely no condensation or emulsion.

I must say, I am intrigued to hear that the UK 500s didn't have the breathers routed to the air cleaners, it does make me wonder if that system didn't work well on the 500 for some reason (?). Just for a lark I might try that and see what happens - it's just a few minutes work to re-route the pipes.
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1975 Triumph T160 Trident
2019 BMW F750GS Sport
1978 Morini 500
'It must be a .....'
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Re: Mayonnaise

Post by 'It must be a .....' »

Hi again, regarding engine breathing; all the 501 Camels I've come across (Italian & French markets) have vented to atmosphere using the same collector box and arrangement similar to UK 500s and there is no available air box connection.
On a 501 Coguaru (Spanish market) the engine breathing system was like early 350s? Rocker cover pipes to a Y connection then linking to the larger pipe from the crankcase (which contained labyrinth baffles) which lead to the rear mudguard and atmosphere; it all appeared to be original.

Good luck
penman
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Re: Mayonnaise

Post by penman »

'It must be a .....' wrote:Hi again, regarding engine breathing; all the 501 Camels I've come across (Italian & French markets) have vented to atmosphere using the same collector box and arrangement similar to UK 500s and there is no available air box connection.
On a 501 Coguaru (Spanish market) the engine breathing system was like early 350s? Rocker cover pipes to a Y connection then linking to the larger pipe from the crankcase (which contained labyrinth baffles) which lead to the rear mudguard and atmosphere; it all appeared to be original.

Good luck
Interesting. I wonder if there was a problem with that arrangement of breathing into the air box. On this bike, the collector box was present, but with no pipes attached. The crankcase breather had a vertical pipe about 200mm long, squeezed in around the collector box and containing a labyrinth baffle. The two right angle pipes from the top of the two air cleaners were present but sealed with sticky tape and the rocker box breather stubs were just open. I think a certain amount of oil mist had been coming out of there judging by how dirty it was. I never tried it like that, I just put it all back to how it "should" be, copying the K2. Then the trouble started!

Hey! I've been lying to you. After I typed the above, I went and had another look at the K2. This time I pulled off all the pipes and there IS mayonnaise in there. Not as much as on the 500, but it is in there. It's just that I used non-transparent pipes on that bike, so I needed to pull them off and have a good look. It hasn't crept up to the air cleaners though.

I'd be interested to hear from anyone else with this collector box arrangement - you do need to pull the pipes off and peer up inside them!

Where do I go from here, ignore it?

Joe.
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Re: Mayonnaise

Post by 72degrees »

penman wrote: When I put it together, the air cleaner was clean and dry and I put new filters in there. A week or so ago when I first noticed this problem, there were lumps of mayonnaise in the air cleaner and the filters were wet. Of course I cleaned and dried it out but within a few miles I could see water droplets in the transparent breather tubes and the white emulsion was creeping up from the collector box. Yes I could try venting the crankcase to air, via a labyrinth breather, I do have one, but I'm not sure I see the point, it shouldn't be doing this. As I've mentioned, my 350 has exactly the same breathing system and it produces absolutely no condensation or emulsion.
But from what you just said in your latest post it does :wink:
I just wondered if the absence of labyrinth baffles in the collector box setup was significant, and that a test as described might reveal that 'normal' emissions were reaching parts they wouldn't reach with them, if you see what I mean.

I'd be a bit concerned if the oil you drain out after each 'flush' is still getting significantly sludgy, rather than less so each time. I'd still, however, give it a good long run with the pre environmental protection emission control arrangements earlier Morinis had, and see what you catch and the state of the oil then.
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