Norton 961 Commando a keeper?

I think what Bluey has is a manual on or off valve that he opens when he wants to drain the air box. The picture he posted shows a black plastic valve with a round knob. I say whatever it takes to live with the old girl ! I prefer the get the oil out of the air box continually method . But rather than allow it to dribble out to the ground or rear tire/brake , I did the larger catch bottle . All of my mods are geared for long sustained riding at high speeds on the interstate. For better or worse this is the kind of riding I end up doing :(
 
The 50c fish tank air valve is all that's keeping me alive, without it the bottle overflows or would do on every run and has once sprayed oil on the rear tyre. I figure that you would need a litre or so of oil in the air-box to be an issue given the depth so its safer to go out for a ride with the valve off, arrive home alive !! and then turn the valve open, Got distracted and left the valve open too long before I empty the bottle the 3 or so times I have too normally and it overflowed as shown all over the floor.

Its on average 150ml I have emailed Norton to see if I can buy a newer oil pump as apparently that can also seep oil into the crank.
 
I am going to be starting a new thread in the upcoming weeks. It will be titled Long Range Norton 961 Introducing the
( Norton 961 LR ) . This is kind of a tribute to the Original Fast Back LR or Interstate models. Of course it will have my twist to all of it . Sort of the world of Norton 961 according to TonyA .
 
Bluey72e said:
Its on average 150ml I have emailed Norton to see if I can buy a newer oil pump as apparently that can also seep oil into the crank.
Click to expand...


Yes , That's a for sure .. The oil is seeping slowly past the feed gears to the returns side . It is NOT leaking past the one way valve . As I is said earlier , if you are still slowly loosing oil to the sump when parked and you have the one way valve already installed . The oil pump has crossover or oil pump pressure regulator leak. Norton said the original pumps could have excessive tolerances (no kidding !)
 
That is an annoying mess.
I had the oil-in-airbox fix kit installed on my 2013 CR.
I was suffering the same problem.
After the kit was installed - no problems anymore.

Before the kit I noticed that my engine was forcing oil out as soon as it started up.
Made me think that there was too much oil in the crankcase at startup that was being forced up into the airbox.
My 961 no longer passes any oil to the airbox.

I can't be certain, but I believe the one way valve from the oil cooler to the oil pump was the trick.
When you shutdown the engine, oil will continue to flow down from the oil cooler to the pump without a functioning one-way valve.
If this allows enough oil to settle in the crankcase sump it will get pressurized on engine startup.

Next time you start your engine, wait 15-20 seconds and see if oil begins draining into the bottle.
If you see oil draining then you may have too much oil sitting in the sump.
Check your one-way valve.
 
It is even easier than that . Before he starts the bike , Check the oil stick and see how much he has lost. If its not on the stick its in the sump .
And there is an easy way to check the one way valve . Remove the oil pump , with an oil can fill the feed side oil entry hole where the banjo bolts on. No oil should start coming out of the one way valve yet. Next , turn the oil pump drive shaft in the direction of engine running rotation CW as viewed from the timing chain side. The feed gears should cause the building oil pressure to "crack" open the one way valve and oil should spurt out . If the oil comes out to freely with no "crack" then valve may be stuck open. Also If you check the return side one way valve leave it off over night or for a few days and check for oil leaking. Same principle on the feed side , leave oil pump off of bike with the feed banjo on . Thoroughly clean oil pump , let it hang over clean bucket . After some days , check the output holes for leaking oil. As I said earlier , I had a properly working check valve (feed side) but oil still got to my sump from the feed side . Oil was bypassing the one way valve through the oil pump and going to the sump. The oil level on the stick when everything is working , should NOT drain down at all . When I park my bike at the end of the season , oil is at the same level 6 months later on the stick . They should all be this way.
 
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Bluey72e said:
I'm suffering, forgot to turn the valve off on the oil bottle after today's run, getting seriously F*%$ing annoying now after every ride.

100ml in the jug 100ml all over the floor, its a pity as everything else is running so well.

Norton 961 Commando a keeper?
Click to expand...
I've had many problems, but never this. I don't have a catch bottle. I have a clear tubing that is usually used for old fish tank filters . Small diameter. I just got my second teaspoon of oil stain because I just changed the oils and went a bit over. Expelled a little after a 70 mile ride. Checked the filter...12400 miles on it and its still white. That is one dept. I've been very fortunate with.
 
TonyA said:
It is even easier than that . Before he starts the bike , Check the oil stick and see how much he has lost. If its not on the stick its in the sump .
And there is an easy way to check the one way valve . Remove the oil pump , with an oil can fill the feed side oil entry hole where the banjo bolts on. No oil should start coming out of the one way valve yet. Next , turn the oil pump drive shaft in the direction of engine running rotation CW as viewed from the timing chain side. The feed gears should cause the building oil pressure to "crack" open the one way valve and oil should spurt out . If the oil comes out to freely with no "crack" then valve may be stuck open. Also If you check the return side one way valve leave it off over night or for a few days and check for oil leaking. Same principle on the feed side , leave oil pump off of bike with the feed banjo on . Thoroughly clean oil pump , let it hang over clean bucket . After some days , check the output holes for leaking oil. As I said earlier , I had a properly working check valve (feed side) but oil still got to my sump from the feed side . Oil was bypassing the one way valve through the oil pump and going to the sump. The oil level on the stick when everything is working , should NOT drain down at all . When I park my bike at the end of the season , oil is at the same level 6 months later on the stick . They should all be this way.
Click to expand...

I have noticed that the oil level on my stick (new longer one from Thiess) is never the same one time half way the next none etc. I have disassembled the oil cooler side one-way check valve and its working correctly as when I crack the cooler banjo side of things NO oil drains.

I think its either the pump check valve stuck open or the pump itself seeping oil through.

Thanks TonyA very useful insight. I will dissemble the oil pump and inspect and test the valve as you say, also have that email in to Norton so fingers crossed I can get a NEW pump one day.

If I fix this She's golden !!
 
Britfan60 said:
I've had many problems, but never this. I don't have a catch bottle. I have a clear tubing that is usually used for old fish tank filters . Small diameter. I just got my second teaspoon of oil stain because I just changed the oils and went a bit over. Expelled a little after a 70 mile ride. Checked the filter...12400 miles on it and its still white. That is one dept. I've been very fortunate with.
Click to expand...

If memory serves me correctly , Did you not get your motor re-ringed or pistons and rings ? This may explain your oil free air box. If the motors were properly done like that all of them would be oil free air box. So you are keeping the oil level on the new longer stick on the knurled section and this is working for you ? Superb !
 
TonyA said:
If memory serves me correctly , Did you not get your motor re-ringed or pistons and rings ? This may explain your oil free air box. If the motors were properly done like that all of them would be oil free air box. So you are keeping the oil level on the new longer stick on the knurled section and this is working for you ? Superb !
Click to expand...

Yes. I had a lot of burnt oil in the rockers. They installed the upgraded banjoless rocker covers and new rings. However, prior to that, there was still never oil (or more than a teaspoon full) in the airbox. Never saturation, never puked. Also yes, 5000 miles on my last oil change. Oil was about 2MM above center of knurled section when filled, oil was dead center of knurled section when I changed it a few weeks ago. So a loss of a couple of ounces? I'm totally impressed. That said, the tranny loses more. 2 to 3 ounces every 1000.
 
Ok, I'm convinced now, its either the lower pressed pump check valve is stuck open or the pump itself is seeping.

If I cant get a pressed version of the check, I may well put one inline above the pre-filter, one of those 0.2 bar crack pressure ones' should hold back the oil when not under suction.

Been 4 weeks that my in-line filter has sat at the Sydney airport apparently, took 4 days to get across the US to international and 4 weeks to go know-where here in Aus, (COVID annoyances for sure) that is if its not been lost i guess..
 
Bluey72e said:
Ok, I'm convinced now, its either the lower pressed pump check valve is stuck open or the pump itself is seeping.

If I cant get a pressed version of the check, I may well put one inline above the pre-filter, one of those 0.2 bar crack pressure ones' should hold back the oil when not under suction.

Been 4 weeks that my in-line filter has sat at the Sydney airport apparently, took 4 days to get across the US to international and 4 weeks to go know-where here in Aus, (COVID annoyances for sure) that is if its not been lost i guess..
Click to expand...

Gotta be real careful with inline check valves positioned before the pump.

This is an issue that even classic Commando owners, who have fitted check valves upstream of the pump have had.

The pressed-in check valve is downstream from the oil pump so the oil pump always has an available supply of oil from the oil tank. The valve simply prevents oil progressing through the pump into the sump when the engine is not running (no pump pressure.) No problem there, on startup pump will always have oil.

If you insert the check valve between the oil tank and pump, and then forget to open the valve before starting the bike – the pump will have no oil supply to pump into the pressure channel. Not a good thing. The Norton boys missed a lot of things on the 961, but pressing the check valve into the pump assembly was the correct way to go.
 
BritTwit said:
Gotta be real careful with inline check valves positioned before the pump.

This is an issue that even classic Commando owners, who have fitted check valves upstream of the pump have had.

The pressed-in check valve is downstream from the oil pump so the oil pump always has an available supply of oil from the oil tank. The valve simply prevents oil progressing through the pump into the sump when the engine is not running (no pump pressure.) No problem there, on startup pump will always have oil.

If you insert the check valve between the oil tank and pump, and then forget to open the valve before starting the bike – the pump will have no oil supply to pump into the pressure channel. Not a good thing. The Norton boys missed a lot of things on the 961, but pressing the check valve into the pump assembly was the correct way to go.
Click to expand...

To be honest I was looking at a .25 bar cracking inline not a complete tap so to speak. Your post though answers a question that I had pondered, in that where in the scheme of things is the check valve as I had noticed that the "feed" was or seemed to be elsewhere.

Started it today with a clear tube, no oil puked at startup, however, went for a 10 min ride up the road and after stopping I actually heard a gurgle from the R6 plastic separator and hay presto opened my air-box drain tap and filled the bottle.

Soooooo..... maybe its the pump after all, but why after a 10 min ride, couple of 2nd 3rd,4th 6.5/7k rpm blaps does it do this, too much oil in the crank would suggest weak scavenge no ?
 
I don't think so . There is too much oil in the sump at the start. Are you willing to pull the drain plug from the sump and get it empty before your next ride ? Collect the oil in a container and measure how much. This is what you are loosing every night to the sump , or if its been days then much more. Try it.
 
I think all years 961's would benefit from the check valve in the return side. Even the new bikes that have the revised return pipe in the oil tank. This way no oil on the return side drops down into the sump. On the new bikes what is in the oil cooler and return hoses will drop into the sump.
 

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