Oil in the airbox/breather

Boss302 said:
Bob
Be sure to download (Richard Coote service manual) for free online. Just search those words. Very informative and well done. You can send him a donation if you like but it's free otherwise.
Click to expand...
Just remember that the "service manual" is more guidelines than actual rules.... The Coote docs are a great resource. Start with the easy stuff so you have some benchmarks.

As Tony suggested, compression test, then I would check your oil pressure and oil pressure relief valve to confirm what your bike does, as some are better than others.

Check each line oil line to confirm good flow both intake and out, and check the oil screen if it hasn't been removed yet. If the oil isn't returning properly, the sump will fill fast then it's go out, which gives you crankcase oil issues.

Check inside your intake to see if you are getting any blowby that could be pushing oil into your air clean that way as well.

Pull the sump plate and look inside.

If your bike sumps then most likely you will always get some oil

As everyone has already suggested, oil level is your friend. But that doesn't mean your oil level will be the same as the next 961. Some can go lower some if you go a drop over the halfway mark you leak like the Valdez. You will need to figure out what works best for your bike but remember you go too low with the already know issues surrounding low oil pressure at idle etc you run the risk of premature wear

Pull the caps off the banjos and see what pressure if anything in or out you are getting

All these things will give you a good benchmark for your bike and save you from coming back and forth with additional questions that will be asked if you keep having issues.
 
BOBBREEKS said:
The previous owner told me he fitted a large touring bottle to catch the excess and tip it back in the oil tank at the end of the ride.
Click to expand...
I'm not sure about doing that. I've found water in the airbox after a wash, along with other grit. I would consider oil that has left the contained system to be contaminated.
 
Stu Bodycote said:
Check scavenge side, from the pick up gauze thats accessible after first removing the sump plate, through to pump and back up to oil tank. At that age it may have a one way valve on the return oil line near to the frame at the front....check that is operating correctly. Oil change for engine after a complete drain is roughly 1.5ltr.
Half the problem is not through design, but through shite tolerance quality control. This is why some guys experience zero oil breather problems, and others are strapping 500ml coke bottles to their breather pipes....Norton's fix is a band aid repair.
Click to expand...
Thanks, when I had the sump off I checked the scavange pipe it was clear and had a gauze on it, (this was before I realised there could be a problem: I checked because of a long history of British bikes gauzes bunged up with gasket goo).
What I will do now is check the one way valve on the return line. I wouldn't be surprised to find the scavange side operating on its last legs by the volume pumping into the airbox.
Thanks to everyone for the heads up, I had no idea it was such an issue and a well trod one at that.
 
City Garage said:
Just remember that the "service manual" is more guidelines than actual rules.... The Coote docs are a great resource. Start with the easy stuff so you have some benchmarks.

As Tony suggested, compression test, then I would check your oil pressure and oil pressure relief valve to confirm what your bike does, as some are better than others.

Check each line oil line to confirm good flow both intake and out, and check the oil screen if it hasn't been removed yet. If the oil isn't returning properly, the sump will fill fast then it's go out, which gives you crankcase oil issues.

Check inside your intake to see if you are getting any blowby that could be pushing oil into your air clean that way as well.

Pull the sump plate and look inside.

If your bike sumps then most likely you will always get some oil

As everyone has already suggested, oil level is your friend. But that doesn't mean your oil level will be the same as the next 961. Some can go lower some if you go a drop over the halfway mark you leak like the Valdez. You will need to figure out what works best for your bike but remember you go too low with the already know issues surrounding low oil pressure at idle etc you run the risk of premature wear

Pull the caps off the banjos and see what pressure if anything in or out you are getting

All these things will give you a good benchmark for your bike and save you from coming back and forth with additional questions that will be asked if you keep having issues.
Click to expand...
Thanks for your suggestions and help, I will do all of that.
 
Hi Team, I have decided to implement a new oil catch tank and a revised routing of breather pipes. So I'm thinking of returning to the mk 1 breather system using the rocker box, (possibly). Just a few questions regarding the configuration.
If anyone has any interior shots of the rocker box I would apreaciate a view. I am particully interested in the attatchment of the banjo bolts. Are these a thread in rocker box or are they straight through a hole and retained by a nut? I also note that quite a few baffles exist, I'd like to see what these look like and how they are fixed in the head. And as a matter of interest the present rocker box breather goes from the back of the head to the bottom front of the oil tank, wouldn't this be the best place for a breather to go, as it contains oil which surely is best served in the engine rather than an airbox/collector tank? I'm loath to keep turning the ashes on this subject but I feel I'm missing something with regards to what has been done in the past. Thanks in anticipation.​
 
Just done this on a customers bike by their request. The original banjo bolts are secured on the other side by a m14 half nut. The left side has a baffle plate covering the banjo opening, the right hand breather fitting is left open straight into the head. I removed the aos, and plumbed the 10mm crankcase spigot straight to the right side, and the left side to the airbox. Luckily I had a spare rocker cover that already had the fittings, so if it doesn't work out, it's easy to reverse. Road tests so far proved successful.
 
Stu Bodycote said:
Just done this on a customers bike by their request. The original banjo bolts are secured on the other side by a m14 half nut. The left side has a baffle plate covering the banjo opening, the right hand breather fitting is left open straight into the head. I removed the aos, and plumbed the 10mm crankcase spigot straight to the right side, and the left side to the airbox. Luckily I had a spare rocker cover that already had the fittings, so if it doesn't work out, it's easy to reverse. Road tests so far proved successful.
Click to expand...
Stu, thanks for the banjo bolt info, how is that left hand baffle plate fixed?And to what? And by aos do you mean the daft plastic box sitting in mid air? Cheers.
 
BOBBREEKS said:
Stu, thanks for the banjo bolt info, how is that left hand baffle plate fixed?And to what? And by aos do you mean the daft plastic box sitting in mid air? Cheers.
Click to expand...
Bob, yes, Stu is referring to the daft plastic box (off a Yamaha R6)
 
I seem to have corrected my oil in airbox and catch bottle problem. At times it was quite severe and messy.
First I added the longer dip stick and run the oil about an inch lower when tank is replenished after sumping relieved by startup and idle. When the bike has recently been running the oil light goes off immediately. After sitting uncertain time it may take 2 seconds to go off. Also oil level is low in tank after sitting. So clearly sumping occuring. I find if I start the bike and keep it at idle while the engine warms I do not get oil vented into the box. If I rev the bike to facilitate warming I do get oil in the box.
I have not added any one way valves into the oil lines or other attempted mods on my 2015 sport which does not have the rocker box vent routing. My bike takes about 5 minutes of warming before it will idle without stalling. When I first got it , it would idle right away but had major rpm surging issues and the dealer remapped it. Now stalling with low idle is the issue.
 
Boss302 said:
I seem to have corrected my oil in airbox and catch bottle problem. At times it was quite severe and messy.
First I added the longer dip stick and run the oil about an inch lower when tank is replenished after sumping relieved by startup and idle. When the bike has recently been running the oil light goes off immediately. After sitting uncertain time it may take 2 seconds to go off. Also oil level is low in tank after sitting. So clearly sumping occuring. I find if I start the bike and keep it at idle while the engine warms I do not get oil vented into the box. If I rev the bike to facilitate warming I do get oil in the box.
I have not added any one way valves into the oil lines or other attempted mods on my 2015 sport which does not have the rocker box vent routing. My bike takes about 5 minutes of warming before it will idle without stalling. When I first got it , it would idle right away but had major rpm surging issues and the dealer remapped it. Now stalling with low idle is the issue.
Click to expand...
Replace the IAC with known good or block it all together.
 
Boss302 said:
I seem to have corrected my oil in airbox and catch bottle problem. At times it was quite severe and messy.
First I added the longer dip stick and run the oil about an inch lower when tank is replenished after sumping relieved by startup and idle. When the bike has recently been running the oil light goes off immediately. After sitting uncertain time it may take 2 seconds to go off. Also oil level is low in tank after sitting. So clearly sumping occuring. I find if I start the bike and keep it at idle while the engine warms I do not get oil vented into the box. If I rev the bike to facilitate warming I do get oil in the box.
I have not added any one way valves into the oil lines or other attempted mods on my 2015 sport which does not have the rocker box vent routing. My bike takes about 5 minutes of warming before it will idle without stalling. When I first got it , it would idle right away but had major rpm surging issues and the dealer remapped it. Now stalling with low idle is the issue.
Click to expand...
 
Apologies if already mentioned. I had my bike serviced and was puzzled by the low engine oil level and kept topping it up. Turns out that using my front wheel chock added a few inches height which affected the oil level. Are you using a chock?
 
Boss302 said:
I seem to have corrected my oil in airbox and catch bottle problem. At times it was quite severe and messy.
First I added the longer dip stick and run the oil about an inch lower when tank is replenished after sumping relieved by startup and idle. When the bike has recently been running the oil light goes off immediately. After sitting uncertain time it may take 2 seconds to go off. Also oil level is low in tank after sitting. So clearly sumping occuring. I find if I start the bike and keep it at idle while the engine warms I do not get oil vented into the box. If I rev the bike to facilitate warming I do get oil in the box.
I have not added any one way valves into the oil lines or other attempted mods on my 2015 sport which does not have the rocker box vent routing. My bike takes about 5 minutes of warming before it will idle without stalling. When I first got it , it would idle right away but had major rpm surging issues and the dealer remapped it. Now stalling with low idle is the issue.
Click to expand...
Hi Boss , Lets talk about wet sumping first and then some ideas about your Idle . Can you verify if you have the oil pump one way valve installed ? Aonther way to gauge is tell us how long does it takes for the oil level to drop down in your tank , one night or one week ? I went from 4 to 6 hours oil tank empty , to 1 week (7 days) oil down 10mm on the stick with the oil pump one way valve . A new pump from Norton now is about 650 pounds I heard . I you haven't pulled off your oil pump that's the only way to see.
Do you have an SC Typhoon ECU ? If so , do you have SXCAR software ? I don't recall if SXTune works with the SC Typhoon. You can use the software to see your valve position % and also the TPS voltage. You can use this to check your TPS throttle have not moved. Mine were around 1.01V . Check your Idle motor and clean out the valve and valve seat. Don't unplug the Idle motor electrical connector when the battery is installed. Unmount the idle motor , do not unplug it electrically. When you key on the bike the idle motor plunger should move during the first few seconds after key on , you might even hear it clicking . If its not moving you may try a replacement.
 
Welshrugby said:
Apologies if already mentioned. I had my bike serviced and was puzzled by the low engine oil level and kept topping it up. Turns out that using my front wheel chock added a few inches height which affected the oil level. Are you using a chock?
Click to expand...
No chock. Always straight and level when checking oil and run up to temp.
 
TonyA said:
Hi Boss , Lets talk about wet sumping first and then some ideas about your Idle . Can you verify if you have the oil pump one way valve installed ? Aonther way to gauge is tell us how long does it takes for the oil level to drop down in your tank , one night or one week ? I went from 4 to 6 hours oil tank empty , to 1 week (7 days) oil down 10mm on the stick with the oil pump one way valve . A new pump from Norton now is about 650 pounds I heard . I you haven't pulled off your oil pump that's the only way to see.
Do you have an SC Typhoon ECU ? If so , do you have SXCAR software ? I don't recall if SXTune works with the SC Typhoon. You can use the software to see your valve position % and also the TPS voltage. You can use this to check your TPS throttle have not moved. Mine were around 1.01V . Check your Idle motor and clean out the valve and valve seat. Don't unplug the Idle motor electrical connector when the battery is installed. Unmount the idle motor , do not unplug it electrically. When you key on the bike the idle motor plunger should move during the first few seconds after key on , you might even hear it clicking . If its not moving you may try a replacement.
Click to expand...
Tony
I ride the bike about each 2 weeks so haven't noticed the time for oil tank to drain. I'll take notice next time I ride it.
I'm almost content to have found a routine to prevent the oil venting. I'm assuming I have whatever the stock 2015 sport oil pump components were as Ive owned the bike since 2017 and it had been a demo prior to that. I haven't been into the pump yet. I'm not sure if the fix that the dealer performed in 2017 involving the idle involved more than a resetting. Probably is the stock ecu for 2015. I'll see if I can identify the ecu when I get a chance. When I bought it , it would surge up to 2000 rpm at idle. It also had issues with the tach reading jumping up to a new false idle reading around 8000. Thanks for your input.
 
Somethings I noticed yesterday when looking inside the Dommie air box.
The drain fitting sits proud (3mm?) of the floor of the box so 3mm of oil would collect before it drains down to the catch bottle.
Also shouldn't the catch bottle have a vent hole at the top somewhere?
 
Well, the whole catch bottle thing is a kludge anyway, compensating for a poor original internal breather design.
But, yes, there should be a vent hole in the cap, or better, a short tube exiting the cap.
In the perfect universe there would be no need for the catch bottle itself, but we all operate in the 961 (Bizarro) universe.
 

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