Smoking 961

BritTwit said:

Wow,

That's an incredible amount of oil in the airbox.
I suppose the previous owner didn't realize that the oil disappearing from the tank was going into the airbox.
That's why it's important to be certain you don't over fill the oil tank.
Did you check the dipstick? Does it have knurling near the bottom of the stick?

I'm not sure when Norton began supplying 961's with the longer dipstick.
If you have this type of longer dipstick then the correct oil level will show on the stick mid way up the knurled section of the stick.
If you fill beyond this point, the excess will end up in your airbox.

If you have the older, shorter dipstick with only high and low marks on the stick it is more difficult to get the correct level.
On these sticks the correct level will be below the low mark, just before the end of the stick.
Norton introduced the new dipstick because many people were over filling their oil tanks, and experiencing the problem you are having.

Which type of dipstick do you have?

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Hey BritTwit, yep I have the older style with no knurling.

I have the older dipstick too. Its at the low mark when cold, dead center when checked after a minute or two running. I don't get oil in the airbox nor do I lose any oil but my bike has been upgraded with new valve covers and breathing system. 2013 Sport.

Had a chat with Norton at Donnington park, they are taking the bike in to do a service and fit (for free) a new longer dipstick and a breather system. Will this fix the issues..........watch this space.

richard-7 said:

Thats gotta be an oil amount in airbox record for this forum. As it fills it also lessens the airbox volume so the bike runs different. Keep it plugged and drain daily. If its not plugged it drips onto your rear brakes while riding.

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That's funny I know of several people who's bike was delivered without the plug including mine and none of us have had oil on our rear brake in 3 or 4 years of riding!

BPHORSEGUY said:

That's funny I know of several people who's bike was delivered without the plug including mine and none of us have had oil on our rear brake in 3 or 4 years of riding!

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Then you’re lucky. My dad rode his bike from niagara falls to texas first month he had it on the road and almost got in an accident when he had no rear brakes. After some inspections as to what was wrong, oil all over his rear disc. Entire rear caliper covered in oil.

Keep in mind some bike drop a lot more oil than others. My dads used to drop a lot.

BPHORSEGUY said:

That's funny I know of several people who's bike was delivered without the plug including mine and none of us have had oil on our rear brake in 3 or 4 years of riding!

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Mine is unplugged. Once in a while I'll see a half of a drop on the ground. Hardly ever. Almost 3k since my last change and the level is the same. I did have a tiny drop today because yesterday I was averaging 75 to 80mph and brought it up to 110 briefly a few times. They just black topped my usual road and maaaaan is it smooth.

My airbox drain has always been unplugged. I noticed that on startup there would be some flow out on the ground, and a very little when I returned from my ride. After several rides I had to add oil to the tank to maintain proper level. Not significant but to me, an annoyance. My airbox drain line is bundled together with the gas tank vent lines, and exits forward, and the left of the rear wheel. I have never gotten any oil on my rear brake rotor, or for that matter, the rear wheel or tire. However, as Richard mentioned, if flow out of an unplugged airbox is very significant, it could present a danger.

BritTwit said:

My airbox drain has always been unplugged. I noticed that on startup there would be some flow out on the ground, and a very little when I returned from my ride. After several rides I had to add oil to the tank to maintain proper level. Not significant but to me, an annoyance. My airbox drain line is bundled together with the gas tank vent lines, and exits forward, and the left of the rear wheel. I have never gotten any oil on my rear brake rotor, or for that matter, the rear wheel or tire. However, as Richard mentioned, if flow out of an unplugged airbox is very significant, it could present a danger.

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My experience is identical! I have several Harleys that are setup identically all with the same results over 30 years and a couple hundred thousand miles!

As Richard pointed out, different bikes appear to behave in different ways.

Ben had 750ml in his airbox...

If he didn't have the plug in, that 750ml of oil would have exited via the drain pipe...

Fast Eddie said:

As Richard pointed out, different bikes appear to behave in different ways.

Ben had 750ml in his airbox...

If he didn't have the plug in, that 750ml of oil would have exited via the drain pipe...

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Yes. That would have been quite a loss. Before my upgrades my bike was burning a lot of that oil. Got new rings installed too. I just can't understand how these bike act so differently. I can understand the getting a bad batch of components that were sourced out, but this oil in the airbox issue varies so wildly. Also, Ben is not the first to report massive amounts of oil like that. There have been others so Ben, don't think you got stuck with the boobie prize. Research these pages and you'll see.

Fast Eddie said:

As Richard pointed out, different bikes appear to behave in different ways.

Ben had 750ml in his airbox...

If he didn't have the plug in, that 750ml of oil would have exited via the drain pipe...

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Yes, over 2 years and 1400 miles. I don't think my bike has lost 1/10 of that in 4 years!

Britfan60 said:

I just can't understand how these bike act so differently. I can understand the getting a bad batch of components that were sourced out, but this oil in the airbox issue varies so wildly.

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The strange differences in the oil in airbox problem are bizarre, and hard to reconcile.
From what I have learned on this site, my own experience, and from listening to the Norton mechanic at my shop there are 3 areas of concern with regard to the oil in airbox issue.

1. Owner unknowingly overfilling the oil tank. We’ve been through this quite bit, and Norton originally supplying the wrong length (too short) dipstick which exacerbated this.

2. Oil migrating to the engine case when the bike has sat unused for a significant period of time. On startup, the crankshaft pushes excess oil into the breather and up to the airbox. This issue can be made even worse by the owner finding the oil level down on the dipstick because some oil is in the engine sump, filling the tank, then starting the engine and driving away, only to hit the brake hard and have the engine stall/backfire or find plumes of smoke jetting from the exhaust.

3. Richard Coote has noted that the oil drain holes in the cylinder head are undersized and do not allow proper oil drainage from the head at higher RPMs. This causes oil to build up in the head and eventually be passed through the rocker cover breather and into the airbox.

Norton has pretty much solved concern #1 by offering the new longer and knurled dipstick.

Issue #2 appears to be a bigger concern for some owners than others. I know that it was my issue since I don’t get a chance to ride my 961 that much. The bike could sit for 4 or 5 weeks before I had a chance to ride it again. I also could see the oil passing from my airbox drain hose on startup sometimes. Proof enough for me to go ahead and get the oil in airbox kit installed. In 300+ miles since the installation there is still no oil in the catch bottle.

Resolving issue #3 would require removal of the cylinder head and drilling out the oil drain holes. This will most likely be a fairly costly expense. This is something that the factory should be doing on all new 961’s.

Hey BritTwit, nicely said. So regarding your points;

1, Had the bike delivered to the factory yesterday. They are going to fit breather kit and a longer dipstick. Hopefully they wont overfill it when they do the service

2, Sounds almost like the old 'wet sumping' that the old Commandos did. When I picked up the bike it had been stationary for a year. So it may have 'wet sumped' and spat it all back into the airbox.

3, Modifying the head will wait until I have a problem big enough to strip the engine. Hopefully I never will.

Now I think about it, when I picked up the bike it could have had 50% of the 750 ml already sitting in the air box. I get the bike delivered back to me at work tomorrow, cant wait for the commute home, may take a longer route.

Thanks again all of you for your help.

Ben

P.s. Off on a tangent, so apologies, South Bay Norton website doesn't seem to operating as a motorcycle trader any more? I was after some of the loud pipes.

Hello , Norton can sell you free flowing exhaust . They are making what was the Motad Norton exhaust system at the factory now. Long open , Short Open and even a decat X-pipe. The fixing bracket on the Cat section is much heavier and should never crack again. Also , give a look at the ZARD 2 into 1 exhaust system for Norton 961.

Look at the Zard system Ben, it looks very cool !

Hi Fast Eddie,

I have mounted the Zard system on one of my 961.
Yes it looks cool, but this is the only one what is good.
I had a lot of bending work to mount the system.
After mounting the big disappointment : It sounds like a frog is living inside.
In Idle you can hear a: quack quack
I wrote this to ZARD and I have never heard something from the manufacturer.
In the moment my bike is at a German exhaust-manufacturer which will do the job much better.
I see one of this systems on a bike from Thiel-motorsport at Glemseck 101.

Cheers

Panetone

Panetone said:

Hi Fast Eddie,

After mounting the big disappointment : It sounds like a frog is living inside.
In Idle you can hear a: quack quack

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Panetone,

is it possible that your Zard system still had the DB killer mounted, and that may account for the weird sound/poor tone quality?
Did you check the tailend of the exhaust to see if it was restricted or open?

Hello BritTwit,

the the exhaust is complete open.
The different without or with DB killer is only the loudness of the frog inside.
My friends are calling my bike "Kermit the frog"
For "Frogsound" the system is much to expensive.

Panetone

Just one thing I don’t get Panetone....

Frogs don’t quack...!

Fast Eddie said:

Just one thing I don’t get Panetone....

Frogs don’t quack...!

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In German they do quack same as ducks.