Where has all my oil gone?

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Hi Lads,

Me again.

Background:

1. I have a 1975 850 MK3 with a 920 conversion done approx. 1000miles ago

2. I'm aware of wet sumping & I'm draining the sump & pouring it back into the oil tank if I leave the bike for a week or two without use (or longer in some cases :roll: )

3. Done a compression test on both cylinders, engine hot, throttle wide open, 180 PSI on both sides.

4. In a previous post I was looking for advice as the bike smokes from the exhausts. Some of you have already explained a test I can do by disconnecting the oil line to the head to see if the oil is coming from above into the combustion chamber through the valve guides.. I have not done this test yet. To be honest I'm nervous disconnecting an oil line which is needed to lubricate the top end :oops:

I'm just really using you guys as a sounding board on my findings.

1. I've been checking the rate at which the bike wet sumps. It approx. drains 130-150ml per 24 hours. In about 7 days 1 litre of oil drains from the tank. In about 2-3 weeks the tank is just about empty. I'm aware of the oil pump recon. work which can be done & the cleaning up of the anti-wetsump valve which is in the MK3 cover. I'm willing to live with the wetsumping until I get some time to recon. the pump etc.

2. All my observations so far have been with the bike in the garage just checking levels every so often etc.

3. Today I did my usual routine, drained the sump, got 350ml of oil, poured it back into the oil tank & went for a 25 mile spin. When I got back I drained the sump & got 300ml out, which took me by surprise. I would have thought the pump would keep the oil moving out of the sump & maybe 100ml would be in there at most after a run?

4. When I poured the oil back into the oil tank I tend to dip it with a steel ruler to see what height the oil is at. It looks like I've lost about 50ml of oil from a 25 mile run!!

5. I can only think of three places the oil can go 1. Oil leak (I've no oil leaks from the engine) 2. Oil is burnt off through the combustion chamber 3. Oil is sitting in the head & not draining out quick enough OR the exhaust valve oil seal is shot OR the rocker spindles are not orientated correctly OR ALL three!!

What do you guys think about my logic, the oil has to go somewhere. I hope to do some touring over the summer & the thought of loosing 50ml of oil every 25 miles would mean I'd need to bring 2 litres of oil for every 1000 miles travelled!!!!!!!

Overall the bike is running well, apart from the Amals, nearly impossible to get a clean tickover! They are balanced really well. I might consider a single carb conversion at some stage, once I've sorted the 'case of the missing oil'!! :D

All the best

Kevin
 
It should be smoking like an over oiled two stroke, is it ??

Cash
 
Hello Kevin,

I have an 850 MarkIII that was going through oil after a complete rebuild. The only thing I didn't do myself was the valve job for the cylinder head and the bore job for my .020 oversize pistons. I finally took my cylinder head off and discovered a huge buildup of baked on deposits on the top of my pistons. Bike had only 2300 miles on the rebuilt engine. Turned out the shop (who shall remain nameless) put my rocker spindles in with the machined flats 180 degrees in the wrong direction. At least they were consistent, because they did it to all four shafts. Apparently the Norton head will fill with oil if the shafts are put in backwards. Also discovered my piston to bore tolearance was .008" on the diameter instead of the factory spec of .004". I fixed the rockers spindles myself and found a custom Harley shop in my area that rebored my cylinders .040" over. They did an awesome job! Not only did they give me the .004" I asked for ,but they got the cylindricity of the bores withing .0002". Pistons are JCC with american made hastings rings. Now she doesn't burn a drop of oil after going thru a full tank of gas. I do not use any check valves on my oil feed line, and don't think wet sumping is related to continuous oil burning.

-Rick
 
click said:
Hi Lads,

Me again.

Background:

1. I have a 1975 850 MK3 with a 920 conversion done approx. 1000miles ago

2. I'm aware of wet sumping & I'm draining the sump & pouring it back into the oil tank if I leave the bike for a week or two without use (or longer in some cases :roll: )

3. Done a compression test on both cylinders, engine hot, throttle wide open, 180 PSI on both sides.

4. In a previous post I was looking for advice as the bike smokes from the exhausts. Some of you have already explained a test I can do by disconnecting the oil line to the head to see if the oil is coming from above into the combustion chamber through the valve guides.. I have not done this test yet. To be honest I'm nervous disconnecting an oil line which is needed to lubricate the top end :oops:

I'm just really using you guys as a sounding board on my findings.

1. I've been checking the rate at which the bike wet sumps. It approx. drains 130-150ml per 24 hours. In about 7 days 1 litre of oil drains from the tank. In about 2-3 weeks the tank is just about empty. I'm aware of the oil pump recon. work which can be done & the cleaning up of the anti-wetsump valve which is in the MK3 cover. I'm willing to live with the wetsumping until I get some time to recon. the pump etc.

2. All my observations so far have been with the bike in the garage just checking levels every so often etc.

3. Today I did my usual routine, drained the sump, got 350ml of oil, poured it back into the oil tank & went for a 25 mile spin. When I got back I drained the sump & got 300ml out, which took me by surprise. I would have thought the pump would keep the oil moving out of the sump & maybe 100ml would be in there at most after a run?

4. When I poured the oil back into the oil tank I tend to dip it with a steel ruler to see what height the oil is at. It looks like I've lost about 50ml of oil from a 25 mile run!!

5. I can only think of three places the oil can go 1. Oil leak (I've no oil leaks from the engine) 2. Oil is burnt off through the combustion chamber 3. Oil is sitting in the head & not draining out quick enough OR the exhaust valve oil seal is shot OR the rocker spindles are not orientated correctly OR ALL three!!

What do you guys think about my logic, the oil has to go somewhere. I hope to do some touring over the summer & the thought of loosing 50ml of oil every 25 miles would mean I'd need to bring 2 litres of oil for every 1000 miles travelled!!!!!!!

Overall the bike is running well, apart from the Amals, nearly impossible to get a clean tickover! They are balanced really well. I might consider a single carb conversion at some stage, once I've sorted the 'case of the missing oil'!! :D

All the best

Kevin
Click to expand...

Hi Kevin can you see any baked on oil deposits on the plugs? If you are not sure what you are looking for post a picture of the plugs...
 
cash said:
It should be smoking like an over oiled two stroke, is it ??

Cash
Click to expand...


Hi Cash,

On the go I can't see any smoke coming from the back of the bike but when I stop & on tickover for a bit, when I rev the engine some smoke comes out, not as bad as a two stroke but very noticeable.

I have a feeling it's something to do with the head filling with oil.

I'll have to do the text of disconnecting the oil line to the head & run the bike for a bit & see if the smoking stops at least then it will tell me if oil is coming from the head.

Kevin
 
Why get more power with a 920 conversion, then detune it with a single carb.
I'm expecting some flak for saying that!
 
plj850 said:
click said:
Hi Lads,

Me again.

Background:

1. I have a 1975 850 MK3 with a 920 conversion done approx. 1000miles ago

2. I'm aware of wet sumping & I'm draining the sump & pouring it back into the oil tank if I leave the bike for a week or two without use (or longer in some cases :roll: )

3. Done a compression test on both cylinders, engine hot, throttle wide open, 180 PSI on both sides.

4. In a previous post I was looking for advice as the bike smokes from the exhausts. Some of you have already explained a test I can do by disconnecting the oil line to the head to see if the oil is coming from above into the combustion chamber through the valve guides.. I have not done this test yet. To be honest I'm nervous disconnecting an oil line which is needed to lubricate the top end :oops:

I'm just really using you guys as a sounding board on my findings.

1. I've been checking the rate at which the bike wet sumps. It approx. drains 130-150ml per 24 hours. In about 7 days 1 litre of oil drains from the tank. In about 2-3 weeks the tank is just about empty. I'm aware of the oil pump recon. work which can be done & the cleaning up of the anti-wetsump valve which is in the MK3 cover. I'm willing to live with the wetsumping until I get some time to recon. the pump etc.

2. All my observations so far have been with the bike in the garage just checking levels every so often etc.

3. Today I did my usual routine, drained the sump, got 350ml of oil, poured it back into the oil tank & went for a 25 mile spin. When I got back I drained the sump & got 300ml out, which took me by surprise. I would have thought the pump would keep the oil moving out of the sump & maybe 100ml would be in there at most after a run?

4. When I poured the oil back into the oil tank I tend to dip it with a steel ruler to see what height the oil is at. It looks like I've lost about 50ml of oil from a 25 mile run!!

5. I can only think of three places the oil can go 1. Oil leak (I've no oil leaks from the engine) 2. Oil is burnt off through the combustion chamber 3. Oil is sitting in the head & not draining out quick enough OR the exhaust valve oil seal is shot OR the rocker spindles are not orientated correctly OR ALL three!!

What do you guys think about my logic, the oil has to go somewhere. I hope to do some touring over the summer & the thought of loosing 50ml of oil every 25 miles would mean I'd need to bring 2 litres of oil for every 1000 miles travelled!!!!!!!

Overall the bike is running well, apart from the Amals, nearly impossible to get a clean tickover! They are balanced really well. I might consider a single carb conversion at some stage, once I've sorted the 'case of the missing oil'!! :D

All the best

Kevin
Click to expand...

Hi Kevin can you see any baked on oil deposits on the plugs? If you are not sure what you are looking for post a picture of the plugs...
Click to expand...

Hi,

The plugs are a sooty black from just pottering around, but they are dry not wet. I did a few plug chops & the top end jetting seems fine.

Does this point in the direction of the head filling with oil?

Kevin
 
Flo said:
Why get more power with a 920 conversion, then detune it with a single carb.
I'm expecting some flak for saying that!
Click to expand...


Hi Flo,

No flak :mrgreen:

The previous owner had let the bike run low on oil & had seized the pistons & damaged the bores. The lower cost option was to get 920 liners, pistons & rings from RGM, which is what he did.

The chap who originally built the bike back in 99 did the repair work on the engine. He was a fantastic chap who built/restored Commando's as a hobby when he retired. He did a grand tour of America with a mate of his on two 74 850 Commando's he built. They shipped them over to the USA from the UK & did, from memory, 7-8K miles touring around without any problems, sadly he has passed on, otherwise I would be giving him a ring for advice!

I think the 920 conversion I have is more about grunt/torque than top end speed. You would need to put in a hot cam & do a few other bits to the engine to get full value from the 920 kit.

I tend to just potter around & mainly want to use the bike for touring & some commuting duties if I can get the usability up a few notches.

My spin on the twin Amals vs any other type of single carb conversion is that if you want to use the bike on a regular basis anything that helps you do this is a good thing. I don't want to look at my Commando as a PITA bike which is hassle to use & will end up sitting in the garage :D I'm fairly handy mechanically but would rather spend my time on top of my Commando rather than underneath it :roll: (OK guys let it rip :lol: )

Kevin
 
The smoke at idle/revving is either valve guides/seals or the reversed spindles. I installed new rings/valves/seals a while back to correct exactly what are you describing. But it didn't fix it. I then discovered that the rocker boxes were filling with oil faster than it could drain (the rocker box drain for the intake side is laughably small...). Further investigation found that at sometime in it's past, a PO installed the spindles 180 out. I turned them around - end of oil burning.

So definitely check that out.

Note . the twin Amals on my 850 will idle smoothly at 600 RPM (Trispark ignition). I'd hate to see you go to the dark side! ;)
 
rmaten4 said:
Hello Kevin,

I have an 850 MarkIII that was going through oil after a complete rebuild. The only thing I didn't do myself was the valve job for the cylinder head and the bore job for my .020 oversize pistons. I finally took my cylinder head off and discovered a huge buildup of baked on deposits on the top of my pistons. Bike had only 2300 miles on the rebuilt engine. Turned out the shop (who shall remain nameless) put my rocker spindles in with the machined flats 180 degrees in the wrong direction. At least they were consistent, because they did it to all four shafts. Apparently the Norton head will fill with oil if the shafts are put in backwards. Also discovered my piston to bore tolerance was .008" on the diameter instead of the factory spec of .004". I fixed the rockers spindles myself and found a custom Harley shop in my area that rebored my cylinders .040" over. They did an awesome job! Not only did they give me the .004" I asked for ,but they got the cylindricality of the bores within .0002". Pistons are JCC with american made hastings rings. Now she doesn't burn a drop of oil after going thru a full tank of gas. I do not use any check valves on my oil feed line, and don't think wet sumping is related to continuous oil burning.

-Rick
Click to expand...

Hi Rick,

That's really interesting. I've come across the info. about the rocker spindles on this forum before. I've never taken the spindles out but it might be something I'll look at after I try disconnecting the oil line to the head & see if the smoke goes away. If it still hangs around I need to start thinking about looking lower down :(

I hoping the bore on my bike is OK, I'm hoping that 180psi on each cylinder is an indication of good health? If the bore tolerance was out on my bike do you know if it would show up on a compression test?

I'm now going to start searching for info. on how to remove the rocker spindles just in case!!

Thanks for the info. it's very useful to know these things.

Kevin
 
mike996 said:
The smoke at idle/revving is either valve guides/seals or the reversed spindles. I installed new rings/valves/seals a while back to correct exactly what are you describing. But it didn't fix it. I then discovered that the rocker boxes were filling with oil faster than it could drain (the rocker box drain for the intake side is laughably small...). Further investigation found that at sometime in it's past, a PO installed the spindles 180 out. I turned them around - end of oil burning.

So definitely check that out.

Note . the twin Amals on my 850 will idle smoothly at 600 RPM (Trispark ignition). I'd hate to see you go to the dark side! ;)
Click to expand...

Hi mike996,

My plan is to do:

1. Disconnect the oil line to the head & run the engine for a while, see if the smoke disappears (Really nervous about doing this!)

2. If the smoke disappears have a look at the spindles.

I should spend more time researching this but I'm going to be a bit cheeky.

Can you move/remove the spindles with the head still attached to the engine?

Re: Twin Amals. I know I could get the carbs worked on, brass slides, inserts etc. I might eventually get this done but I'd like a solution sooner rather than later as I'm planning touring Scotland over the summer & might also nip over to the Isle of Man.

I got a Pazon EI for my Commando, I thought long & hard about the Trispark but just felt It was a bit too new & untested in the 'real' world. It is on my shopping list which is growing each time I take the bike out :mrgreen:

So a bit more testing for me to track the fault & a look at the spindles.

Thanks lads for all your advice & help.

Kevin
 
click said:
cash said:
It should be smoking like an over oiled two stroke, is it ??

Cash
Click to expand...


Hi Cash,

On the go I can't see any smoke coming from the back of the bike but when I stop & on tickover for a bit, when I rev the engine some smoke comes out, not as bad as a two stroke but very noticeable.

I have a feeling it's something to do with the head filling with oil.

I'll have to do the text of disconnecting the oil line to the head & run the bike for a bit & see if the smoking stops at least then it will tell me if oil is coming from the head.

Kevin
Click to expand...

What color is the smoke is it a bluey grey or very black?

As far as the spark plug color a sort of matt/sooty black would suggest an engine running rich at idle if there were was a sort of lumpy black deposit that would indicate excessive oil being burned in the combustion chamber.
 
Hi Kevin,

If your bore tolerance is a little off, like mine was, it probably will not show up on a compression test. My compression test showed 155 PSI even though the bores/pistons were .008" of diametral clearance. As far as removing a rocker spindle on the bike: I have never tried it but I suppose its possible. You are supposed to get the head to over 350 degrees F and then use a slide hammer to pull the rocker. Most guys do this with the head off and they heat it in an oven. The problem you will face by trying to pull a rocker on the bike is getting the head hot enough and not damaging anything. You have too much invested in it to start taking torches to it. I would pull it first.
Good Luck
-Rick
 
The spindles will turn in the head. Heat the head by running the bike for a while. You may need to slightly withdraw the spindles - maybe 1/4" before they will turn with a big screwdriver/wrench. I had to withdraw one but the other 3 didn't need anything other than twisting. Be sure to have the specific valve closed (as if you were adjusting the tappet) otherwise it is much harder to turn the spindle. To withdraw them you can make a puller with a long bolt of the correct thread (can't recall what that is) and a socket large enough so that the spindle can pull up inside. You will NOT need to pull the spindles out so even a short socket will work fine.
 
plj850 said:
click said:
cash said:
It should be smoking like an over oiled two stroke, is it ??

Cash
Click to expand...


Hi Cash,

On the go I can't see any smoke coming from the back of the bike but when I stop & on tickover for a bit, when I rev the engine some smoke comes out, not as bad as a two stroke but very noticeable.

I have a feeling it's something to do with the head filling with oil.

I'll have to do the text of disconnecting the oil line to the head & run the bike for a bit & see if the smoking stops at least then it will tell me if oil is coming from the head.

Kevin
Click to expand...

What color is the smoke is it a bluey grey or very black?

As far as the spark plug color a sort of matt/sooty black would suggest an engine running rich at idle if there were was a sort of lumpy black deposit that would indicate excessive oil being burned in the combustion chamber.
Click to expand...

Hi cash,

I'd say it was more grey than black. Whats the diagnosis doctor :D ?

Kevin
 
click said:
Hi Lads,

Me again.

Background:

1. I have a 1975 850 MK3 with a 920 conversion done approx. 1000miles ago

2. I'm aware of wet sumping & I'm draining the sump & pouring it back into the oil tank if I leave the bike for a week or two without use (or longer in some cases :roll: )

3. Done a compression test on both cylinders, engine hot, throttle wide open, 180 PSI on both sides.

4. In a previous post I was looking for advice as the bike smokes from the exhausts. Some of you have already explained a test I can do by disconnecting the oil line to the head to see if the oil is coming from above into the combustion chamber through the valve guides.. I have not done this test yet. To be honest I'm nervous disconnecting an oil line which is needed to lubricate the top end :oops:

I'm just really using you guys as a sounding board on my findings.

1. I've been checking the rate at which the bike wet sumps. It approx. drains 130-150ml per 24 hours. In about 7 days 1 litre of oil drains from the tank. In about 2-3 weeks the tank is just about empty. I'm aware of the oil pump recon. work which can be done & the cleaning up of the anti-wetsump valve which is in the MK3 cover. I'm willing to live with the wetsumping until I get some time to recon. the pump etc.

2. All my observations so far have been with the bike in the garage just checking levels every so often etc.

3. Today I did my usual routine, drained the sump, got 350ml of oil, poured it back into the oil tank & went for a 25 mile spin. When I got back I drained the sump & got 300ml out, which took me by surprise. I would have thought the pump would keep the oil moving out of the sump & maybe 100ml would be in there at most after a run?

4. When I poured the oil back into the oil tank I tend to dip it with a steel ruler to see what height the oil is at. It looks like I've lost about 50ml of oil from a 25 mile run!!

5. I can only think of three places the oil can go 1. Oil leak (I've no oil leaks from the engine) 2. Oil is burnt off through the combustion chamber 3. Oil is sitting in the head & not draining out quick enough OR the exhaust valve oil seal is shot OR the rocker spindles are not orientated correctly OR ALL three!!

What do you guys think about my logic, the oil has to go somewhere. I hope to do some touring over the summer & the thought of loosing 50ml of oil every 25 miles would mean I'd need to bring 2 litres of oil for every 1000 miles travelled!!!!!!!

Overall the bike is running well, apart from the Amals, nearly impossible to get a clean tickover! They are balanced really well. I might consider a single carb conversion at some stage, once I've sorted the 'case of the missing oil'!! :D

All the best

Kevin
Click to expand...


The other place it can go, which I don't think has got a mention yet, is past the crankshaft seal into the primary.
 
Greetings,
If you suspect that your rocker arm spindles may have been installed incorrectly you do not have to pull the head off to remove them. Heating the head is recommened, although according to the repair manual (Haynes) putting the head in boiling water is all that is required. Being that water boils at 212F (100C) I think Mike996s suggestion of running the bike up to operating temp and doing the work with engine intact is probably ten times less work. According to the INOA Tech Digest the proper orientation of the smooth surface type rocker spindles is flat spots toward the outside of the engine (IE away from each other). You will want to remove the rocker cover in order to observe the valve action, pull spindle when valve is closed, AND prevent the washers (spring type on the inside, plain on the outside) from falling out of place. You need not completely remove the spindle, but you will have to pull it far enough out to see where the flat spot is. To pull mine I welded a washer onto the head of a 5/16 fine thread bolt (yes I know it is not "the" correct thread, but close enough) hooked the washer with a small slide hammer and tapped the spindle out. Good luck, hope you find a simple solution to your oil problem.

GB
 
What is the breather set up you have on the bike? Incidentally the sump always has oil in it. As soon as you stop the motor, everything runs into it so it is not unusual to recover 200ml. I do think your wet sumping via the feed line is excessive, agree its time to recon the pump.

Mick
 
geo46er said:
Greetings,
If you suspect that your rocker arm spindles may have been installed incorrectly you do not have to pull the head off to remove them. Heating the head is recommened, although according to the repair manual (Haynes) putting the head in boiling water is all that is required. Being that water boils at 212F (100C) I think Mike996s suggestion of running the bike up to operating temp and doing the work with engine intact is probably ten times less work. According to the INOA Tech Digest the proper orientation of the smooth surface type rocker spindles is flat spots toward the outside of the engine (IE away from each other). You will want to remove the rocker cover in order to observe the valve action, pull spindle when valve is closed, AND prevent the washers (spring type on the inside, plain on the outside) from falling out of place. You need not completely remove the spindle, but you will have to pull it far enough out to see where the flat spot is. To pull mine I welded a washer onto the head of a 5/16 fine thread bolt (yes I know it is not "the" correct thread, but close enough) hooked the washer with a small slide hammer and tapped the spindle out. Good luck, hope you find a simple solution to your oil problem.

GB
Click to expand...

Hi,

Thanks for the info.

I plan on running the engine with the exhaust rocker covers off to see if oil is pooling in the head, I'll then make a decision what to do.

Kevin
 
Pulling the spindles is not a big job and is done on to bike. Do not spin them 180 unless you have confirmed that they are in wrong(facing the center of the head). There are different kind of spindles. Some have the flats, some are scrolled and some have just a hole. I had some with just a hole and ground the flat in and oriented them properly. Here goes,

1. Familiarize yourself with the parts breakdown and the operation of the rockers.
2. Pull tank, valve covers and spindle caps and covers.
3. Because these are hard I used a different thread and got away with it. 5/16, I believe. With a socket on the threaded rod and a washer and nut on the end and you have a slide hammer to remove the spindles.
4. These spindles are a somewhat press fit on the outside and less restrictive on the inside so heat about the outer area will be all that needed. A Map gas torch is cheap and very hot. Much hotter then propane.
5. At this point take note of the assembly order of the rocker spring (inboard) and thrust washer(outboard) of the rocker.
6. Rotate engine to relieve pushrod. Do one at a time.
Don't put the slide hammer in to the spindle yet. Wait until you get it hot.
7. Heat the area around the spindle realizing the head will dissipate heat quickly. Once you feel you have some heat into the area, thread tool into the spindle a few turns and dap it out with the socket against the washer /nut.
They may just come right but more heat will most likely be needed.
8. Rotate the spindle to face the flat away from the center of the head on all spindles. Exhaust facing forward, Intake facing the rear.
9. There is a oil hole that line up with the notch in the spindle when in place. Be sure it is evident.

That should keep you busy for a while. We'll be watching your post to help you follow through.
 
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