Oil Issue.........

coomo · Dec 29, 2019

Have ridden about 300 wonderful miles since rebuild.A few teething issues arose, nothing major.
Then a rider behind me noticed I was "burning oil" I was.After bike warmed up.
Contacted my build guy.He went over it, and confirmed engine was all good.
Next on list of suspects, had to be crankcase pressure issues.Spec as follows.
CNW/Comstock breather mounted on lower case,returned to oil (central) tank
Holland Norton works Anti wet sump valve.
Return to oil tank via magnafine filter.
Front oil tank breather has spigot, to oil line to catch tank vented to atmosphere.
All via "braided" oil lines.
CNW breather appears to "fart" when kicked over.Checked.
Holland wet sump valve,removed.Checked.
Oil tank drained,Compressed air blown through.Checked.
Front spigot had some evidence of "mayonaise" oil deposits.Mmmm.
Return to tank via "Braided lines" Had kink near top hat.Mmmm.
Catch tank, had light oil deposits,(mayonasse again).Plus filter was blocked .Mmmm.
First job.Remove "rubbish braided lines"Build Mistake no1.These are not quality braided lines.Basically plastic tube covered in stainless steel.
Will be replaced with Aeroquip 3/8th black oil lines.No issues with kinks either.
Run out of hose.Will purchase more next week.Hopefully will cure.......

maylar · Dec 29, 2019

Under what conditions does it burn oil? Idle, blipping throttle, deceleration or acceleration under load? Knowing that will determine if the oil is getting past the rings or the valves.

MexicoMike · Dec 29, 2019

Anytime someone mentions "recent rebuild" and "oil burning" I think: Rocker arm spindles installed backwards.

Dances with Shrapnel · Dec 29, 2019

Not sure what I am looking at with picture 007.jpg (lower LH corner above). It’s clearly a screw on trap of some type. If that is a breather line with a sintered metal filter nib often found on compressed air line systems it will choke up with oil and especially with the mayonnaise. If sintered then mayonnaise will freeze up.

A breather line really must be more or less clear to atmosphere.

maylar · Dec 29, 2019

I've seen oil froth like that once before, when the 2 oil lines at the engine were reversed on a 72 combat. The motor didn't last long.

o0norton0o · Dec 29, 2019

Mayonnaise is one of those things that indicates water in the oil. In an air cooled engine, like our nortons, it just means that you haven't gotten the oil up to temperature long enough to exhaust all the moisture from the air inside the crankcase completely. You warmed the engine up but not enough to evaporate the entire system's naturally occurring concentration of water permeating the air inside the engine. The longer you run the engine, the less mayo you will see.

My water cooled truck has a towing package which has a big radiator. If I take short trips I always can see a little may on the fill cap. On long trips it's clean because the engine heat burns it off. On a water cooled engine, it can be a sign of the head gasket failure beginning, but not on air cooled engines..

I see you have a central oil tank too with some creative plumbing. Does that mean you have a '70 frame, because the cross member of that frame usually blocks the comstock sump breather, unless you machined the cases to mount the breather where the combat style breather is mounted...

anyway, as mike said, check the weep hole direction of your rocker arm spindles, and your intake valve seals. Hopefully you didn't drop a wristpin circlip because that's a tear down situation. AMHIK

RoadScholar · Dec 29, 2019

First, are you communicating with your "Build Guy" ? Only fair to give him first shot at addressing your questions/concerns, and, if appropriate, give him first shot at correcting any build errors, assuming he continues to be worthy of your trust.

In any event 300 miles, depending on how you rode them, may or may not be enough to seat the rings. Have you checked and re-torqued the engine fasteners? (all fasteners for that matter). Have you checked and reset, as necessary, the valve lash? The ambient air temp where you are riding is low; good news and bad news: engine heat get dissipated more rapidly, but may be less uniform throughout the engine. Fuel mixture tends to go toward lean which cam make a normal break-in period a cat and mouse game of avoiding detonation when you apply load.

If the engine fasteners are good and the valves have the correct clearance I suggest you expose the engine to some limited full bore pulls (high loads with large throttle openings while not exceeding 5500 RPM). If you have the feel and sensitivity to hear your engine tell you when your well intentioned break-in method is too aggressive you will know when to back down, let your engine stabilize so that you can go back up and challenge the "tight" spots, gently and not for too long.

After about 200+ more miles, with attention to engine fastener torque, valve lash, ignition timing and carb sync, a leak down test, or a group of compression tests should yield results that near identical. If they do and you are still burning oil, the list of other possibilities becomes labor intensive, depressing and possibly expensive, some are already in evidence above, the rest of the list will get here eventually.

Hope all works out with minimal drama.

Best

coomo · Dec 29, 2019

maylar said:
Under what conditions does it burn oil? Idle, blipping throttle, deceleration or acceleration under load? Knowing that will determine if the oil is getting past the rings or the valves.

On tickover, under acceleration.

coomo · Dec 29, 2019

RoadScholar said:
First, are you communicating with your "Build Guy" ? Only fair to give him first shot at addressing your questions/concerns, and, if appropriate, give him first shot at correcting any build errors, assuming he continues to be worthy of your trust.

In any event 300 miles, depending on how you rode them, may or may not be enough to seat the rings. Have you checked and re-torqued the engine fasteners? (all fasteners for that matter). Have you checked and reset, as necessary, the valve lash? The ambient air temp where you are riding is low; good news and bad news: engine heat get dissipated more rapidly, but may be less uniform throughout the engine. Fuel mixture tends to go toward lean which cam make a normal break-in period a cat and mouse game of avoiding detonation when you apply load.

If the engine fasteners are good and the valves have the correct clearance I suggest you expose the engine to some limited full bore pulls (high loads with large throttle openings while not exceeding 5500 RPM). If you have the feel and sensitivity to hear your engine tell you when your well intentioned break-in method is too aggressive you will know when to back down, let your engine stabilize so that you can go back up and challenge the "tight" spots, gently and not for too long.

After about 200+ more miles, with attention to engine fastener torque, valve lash, ignition timing and carb sync, a leak down test, or a group of compression tests should yield results that near identical. If they do and you are still burning oil, the list of other possibilities becomes labor intensive, depressing and possibly expensive, some are already in evidence above, the rest of the list will get here eventually.

Hope all works out with minimal drama.

Best

Engine guy is the most respected builders/racers in UK.He took bike back and performed all relevant checks, re torques etc.

coomo · Dec 29, 2019

o0norton0o said:
Mayonnaise is one of those things that indicates water in the oil. In an air cooled engine, like our nortons, it just means that you haven't gotten the oil up to temperature long enough to exhaust all the moisture from the air inside the crankcase completely. You warmed the engine up but not enough to evaporate the entire system's naturally occurring concentration of water permeating the air inside the engine. The longer you run the engine, the less mayo you will see.

My water cooled truck has a towing package which has a big radiator. If I take short trips I always can see a little may on the fill cap. On long trips it's clean because the engine heat burns it off. On a water cooled engine, it can be a sign of the head gasket failure beginning, but not on air cooled engines..

I see you have a central oil tank too with some creative plumbing. Does that mean you have a '70 frame, because the cross member of that frame usually blocks the comstock sump breather, unless you machined the cases to mount the breather where the combat style breather is mounted...

anyway, as mike said, check the weep hole direction of your rocker arm spindles, and your intake valve seals. Hopefully you didn't drop a wristpin circlip because that's a tear down situation. AMHIK

yes its a 70 frame.The breather was machined into case.Im happy engine is all good as per previous response.

maylar · Dec 29, 2019

coomo said:
On tickover, under acceleration.

Likely oil ring sealing problem. Valve seals would be more evident on decel, where vacuum is highest.
Check compression?

coomo · Dec 29, 2019

Dances with Shrapnel said:
Not sure what I am looking at with picture 007.jpg (lower LH corner above). It’s clearly a screw on trap of some type. If that is a breather line with a sintered metal filter nib often found on compressed air line systems it will choke up with oil and especially with the mayonnaise. If sintered then mayonnaise will freeze up.

A breather line really must be more or less clear to atmosphere.

Yes that catch tank , for some reason has a filter.Plus its one way,as its "arrowed" it does blow through clear.However, perhaps it wasnt prior to cleaning.Ill remove the filter.My hunch tells me this may have caused my issues.

RoadScholar · Dec 29, 2019

coomo said:
Engine guy is the most respected builders/racers in UK.He took bike back and performed all relevant checks, re torques etc.

Good, and smart. So many times I see posts that mirror the cliche: Ready, Fire, Aim. Someone has a bad experience with a vendor or service provider and goes off on the part/service without speaking with the seller/provider first.

Sounds like your builder has some worthy credentials, so he should put things right for you. Do follow-up, if you can.

Best

texasSlick · Dec 29, 2019

MexicoMike said:
Anytime someone mentions "recent rebuild" and "oil burning" I think: Rocker arm spindles installed backwards.

I would agree. However, in this case, I do not think it would have taken 300 miles for the oil burning to start ..... It would have happened right after first start up.

There is something else going on ......

Slick

coomo · Dec 29, 2019

maylar said:
I've seen oil froth like that once before, when the 2 oil lines at the engine were reversed on a 72 combat. The motor didn't last long.

Thanks for scaring me Dave! Oil lines are correct though.

coomo · Dec 29, 2019

I look at it this way.Something has changed.Obviously.Lets assume that the engine is fine.I do.Its been checked by builder.I personally think its the catch tank not "breathing" and/or those crap lines I used.When I pulled it apart yesterday the return to tank from CNW breather had a kink in it.Now.Lets assume when I first fitted it,it didnt have a kink.I have removed side panel on many occasions.Its tight in there now there is a catch tank.Maybe the last time I refitted side panel, I kinked oil line.
Something else just came to mind.I wonder if Magnafine filter is directional??!!

Steves · Dec 29, 2019

I may have missed this and I take at face value your bike is burning oil because you said it is. At what rate does it burn oil. What do the plugs look like. I had a problem on the left cylinder with burning oil,it was quite an education tracking it down.
With the Mayo this was also a problem for me. I did an oil change, only had enough oil to get to about 5mm below the low mark, thought it will be alright until I get some more oil. Then, because I was checking oil level more, I noticed no more Mayo! Since then that's where I set the oil level. This has been discussed before, I had to see it with my own eyes before I paid attention.

rvich · Dec 29, 2019

The mayonnaise a product of blow-by?

coomo · Dec 29, 2019

Steves said:
I may have missed this and I take at face value your bike is burning oil because you said it is. At what rate does it burn oil. What do the plugs look like. I had a problem on the left cylinder with burning oil,it was quite an education tracking it down.
With the Mayo this was also a problem for me. I did an oil change, only had enough oil to get to about 5mm below the low mark, thought it will be alright until I get some more oil. Then, because I was checking oil level more, I noticed no more Mayo! Since then that's where I set the oil level. This has been discussed before, I had to see it with my own eyes before I paid attention.

Steve, everything is as it should be.It hasnt been happening to the extent of checking it.Once noticed,I stopped riding it.My guy checked it all.I will put in fresh oil after its buttoned up obviously.The first 300 miles, no mayo, nothing at all deposited in catch tank.my feeling is that it was due to a blockage or restriction in oil lines, not venting correctly.

kommando · Dec 29, 2019

When you burn 1 gallon of fuel it creates nearly 1 gallon of water, in a car started from cold you see this as water coming out of the exhaust. When the engine is warm the water becomes invisible but if the rings are not bedded in and the bores glazed then this water ends up in the oil and hence the mayo.

Oil Issue.........

coomo

Attachments

maylar

MexicoMike

Dances with Shrapnel

maylar

o0norton0o

RoadScholar

coomo

coomo

coomo

maylar

coomo

RoadScholar

texasSlick

coomo

coomo

Steves

rvich

coomo

kommando

Similar threads