Norton 961 massive oil leak.

Raincityrider · Nov 17, 2024

Hello,

Just went to start up my 961, it’s been sitting for 3 months. As I pulled the bike out I noticed a massive amount of oil on the floor. At first, it seems the oil came out of the over flow tube. Could that happen? It’s a large amount around the back wheel. A pool of it just about all the oil.
Any help would be greatly appreciated!

Richard Tool · Nov 17, 2024

Wet sumped and got past the crank seal into the primary drive case - from there out the case joint ? ? If indeed this is what happened you will need to wash the clutch plates .

BritTwit · Nov 17, 2024

Raincityrider said:
Hello,

Just went to start up my 961, it’s been sitting for 3 months. As I pulled the bike out I noticed a massive amount of oil on the floor. At first, it seems the oil came out of the over flow tube. Could that happen? It’s a large amount around the back wheel. A pool of it just about all the oil.
Any help would be greatly appreciated!

First thing I would check is the strainer on the oil supply line from the oil tank to the oil pump. If the O Ring in the strainer is not seated properly, oil will pass the O ring and slowly run down the hose, on to the crankcase and to the back of the engine area. And yes, over time this can empty the oil tank onto your garage floor. Ask me how I know.

If this is your problem, the lower part of the strainer will be wet with oil, as well as the hose, and the lower pump housing.
Easy fix, is to open the strainer, and re-seat the O ring. But first pinch the hose above the strainer, because there may still be some oil left in the tank. You don't want any remaining oil in the tank spill out all over the place.

I hope this helps.

BritTwit · Nov 17, 2024

Oh yeah, this thread should be moved to the Modern Norton Forum.

Richard Tool · Nov 17, 2024

BritTwit said:
Oh yeah, this thread should be moved to the Modern Norton Forum.

Well I suppose I should withdraw my answer .. if I may . LOL

TonyA · Nov 18, 2024

Raincityrider said:
Hello,

Just went to start up my 961, it’s been sitting for 3 months. As I pulled the bike out I noticed a massive amount of oil on the floor. At first, it seems the oil came out of the over flow tube. Could that happen? It’s a large amount around the back wheel. A pool of it just about all the oil.
Any help would be greatly appreciated!

You have to trace where the oil came from , then report back . There will be evident traces of oil somewhere . The oil was already on the floor and you never started the bike ? There is not enough oil in the oil tank to overflow the crankcase even if you wet sumped all of it . May very well be the oil line/filter screen like Brit Twit said if you have one . Was the bike serviced before parking it ?

BritTwit · Nov 18, 2024

TonyA said:
You have to trace where the oil came from , then report back . There will be evident traces of oil somewhere .

That's right.
If it is the strainer, the O ring leak is a relatively slow one. So takes a few weeks for the tank to empty onto the floor.
In my case, the bike was on the side stand, leaning to the left. The oil leaked down the hose, to the lower oil pump housing, across the right crankcase, onto the sump cover, then onto the left bottom of the crankcase and then dripped off onto the floor.
This happened in the late Fall, the bike hadn't been ridden in weeks, nor had I checked the bike in weeks.

Raincityrider · Nov 18, 2024

TonyA said:
You have to trace where the oil came from , then report back . There will be evident traces of oil somewhere . The oil was already on the floor and you never started the bike ? There is not enough oil in the oil tank to overflow the crankcase even if you wet sumped all of it . May very well be the oil line/filter screen like Brit Twit said if you have one . Was the bike serviced before parking it ?

Hello. So the bike is still very new to me. It was serviced by the dealer I purchased it from. I ride the Norton parked it and that was 3 months ago. My wife and I just had a kid so it’s been sitting. Yesterday I got to fire it up and notice the puddle by the back wheel.

Raincityrider · Nov 18, 2024

BritTwit said:
That's right.
If it is the strainer, the O ring leak is a relatively slow one. So takes a few weeks for the tank to empty onto the floor.
In my case, the bike was on the side stand, leaning to the left. The oil leaked down the hose, to the lower oil pump housing, across the right crankcase, onto the sump cover, then onto the left bottom of the crankcase and then dripped off onto the floor.
This happened in the late Fall, the bike hadn't been ridden in weeks, nor had I checked the bike in weeks.

Thank you! I’ll hopefully be able to have time this weekend to do some exploratory
Work on it.

Raincityrider · Nov 18, 2024

BritTwit said:
First thing I would check is the strainer on the oil supply line from the oil tank to the oil pump. If the O Ring in the strainer is not seated properly, oil will pass the O ring and slowly run down the hose, on to the crankcase and to the back of the engine area. And yes, over time this can empty the oil tank onto your garage floor. Ask me how I know.

If this is your problem, the lower part of the strainer will be wet with oil, as well as the hose, and the lower pump housing.
Easy fix, is to open the strainer, and re-seat the O ring. But first pinch the hose above the strainer, because there may still be some oil left in the tank. You don't want any remaining oil in the tank spill out all over the place.

I hope this helps.

I’ll give that a look! Thank you for the help!

TonyA · Nov 18, 2024

Raincityrider said:
Yesterday I got to fire it up and notice the puddle by the back wheel.

This may be wet sumping , excess crankcase oil is pushed to the airbox and out the drain. Before you start the bike , check the oil on the dip stick and see if there is any in the oil tank. Also let us know what year is the bike and what type of crankcase breather you have. Meaning is it going to the rocker box first or straight to the air box.

City Garage · Nov 18, 2024

TonyA said:
This may be wet sumping , excess crankcase oil is pushed to the airbox and out the drain. Before you start the bike , check the oil on the dip stick and see if there is any in the oil tank. Also let us know what year is the bike and what type of crankcase breather you have. Meaning is it going to the rocker box first or straight to the air box.

To follow what Tony said pull the seat and check the airbox for oil as well. If it leaked that much, then the filter will/should be soaked, and the airbox should have some residue in the bottom as well.

kev · Nov 18, 2024

Do you have a pic of the oil on the floor? Reason I ask is that mine leaked about 100ml (from the airbox) and it looked like LOTS on the floor and I totally panicked as it looked catastrophic....and it wasn't

K

TonyA · Nov 19, 2024

City Garage said:
To follow what Tony said pull the seat and check the airbox for oil as well. If it leaked that much, then the filter will/should be soaked, and the airbox should have some residue in the bottom as well.

Hi Lance , Some of the bikes had the air box drain tube plugged and lots of oil would build up in there and drown the intake during braking. You have seen this already I'm sure.

Raincityrider · Jan 20, 2025

So I have my 2013 in a shop now. The me mechanic says there is a heavy oil mist coming out of the crankcase breather. Does anyone know how to solve this issue? He seems stumped.

Raincityrider · Jan 20, 2025

TonyA said:
Hi Lance , Some of the bikes had the air box drain tube plugged and lots of oil would build up in there and drown the intake during braking. You have seen this already I'm sure.

So I have my 2013 in a shop now. The me mechanic says there is a heavy oil mist coming out of the crankcase breather. Does anyone know how to solve this issue? He seems stumped.

Raincityrider · Jan 20, 2025

City Garage said:
To follow what Tony said pull the seat and check the airbox for oil as well. If it leaked that much, then the filter will/should be soaked, and the airbox should have some residue in the bottom as well.

So I have my 2013 in a shop now. The me mechanic says there is a heavy oil mist coming out of the crankcase breather. Does anyone know how to solve this issue? He seems stumped.

BritTwit · Jan 20, 2025

Since you have a 2013 machine, you may not have the later developed Crankcase breather fix kit fitted to your bike.
It was not unusual for early 961s to fill the air box with oil via the breather.

Post in thread 'Off My Rocker Box'

Aug 19, 2023

Here is the complete TSB.
Maybe someone can move it over to the tech help site.

Crankcase Breather Kit

Thanks for the info. I'll definitely discuss this with my dealer when the kit comes in. Tony, Richard thanks again. Fred

www.accessnorton.com

TonyA · Jan 20, 2025

Raincityrider said:
So I have my 2013 in a shop now. The me mechanic says there is a heavy oil mist coming out of the crankcase breather. Does anyone know how to solve this issue? He seems stumped.

Hello Raincityrider , Read through this oil in air box thread because some or all of it may apply to your bike . If you have more questions then post them .

Post in thread 'Crankcase Breather Kit'

Aug 10, 2017

Well my ship has finally come in.

I placed my order for the Breather update kit in April, and it has finally arrived at the dealer.

$325.00 and it came in the pictured ziplock plastic bag, sans any instructions.
Not even a packing list of parts to check either. A bit underwhelming to say the least.
I’ll just be happy if the kit solves the oil use and airbox issues.
I’m going to have the dealer do the installation. However, I'll have to wait for Aug 22nd until they have an opening.
I’m posting pics/docs from Fotki since Photobucket shut me down, and I’m not too proficient with their...

Post in thread '2015 commando 961...Oil in airbox'

Jul 29, 2022

Sticky tyres718 said:
I realise this topic has been chewed over before but actually finding a definite remedy is very difficult.
Anyone able to tell me a solution to the problem of oil in the airbox?
Is it a combination of the longer dipstick and breather rocker cover fix from Norton is has some clever dick found a way round having to fit an ugly plastic part to my beautiful bike.
I currently have the original "short dipstick" and I'm running a catch bottle... Getting roughly 300ml of oil every ride with a oil level at the top mark when I start off.

Your introduction leaves little wiggle room. I would...

Raincityrider · Jan 20, 2025

TonyA said:
Hello Raincityrider , Read through this oil in air box thread because some or all of it may apply to your bike . If you have more questions then post them .

Post in thread 'Crankcase Breather Kit'

Aug 10, 2017

Well my ship has finally come in.

I placed my order for the Breather update kit in April, and it has finally arrived at the dealer.

$325.00 and it came in the pictured ziplock plastic bag, sans any instructions.
Not even a packing list of parts to check either. A bit underwhelming to say the least.
I’ll just be happy if the kit solves the oil use and airbox issues.
I’m going to have the dealer do the installation. However, I'll have to wait for Aug 22nd until they have an opening.
I’m posting pics/docs from Fotki since Photobucket shut me down, and I’m not too proficient with their...

BritTwit

Post in thread '2015 commando 961...Oil in airbox'

Jul 29, 2022

Sticky tyres718 said:

I realise this topic has been chewed over before but actually finding a definite remedy is very difficult.
Anyone able to tell me a solution to the problem of oil in the airbox?
Is it a combination of the longer dipstick and breather rocker cover fix from Norton is has some clever dick found a way round having to fit an ugly plastic part to my beautiful bike.
I currently have the original "short dipstick" and I'm running a catch bottle... Getting roughly 300ml of oil every ride with a oil level at the top mark when I start off.

Click to expand...

Your introduction leaves little wiggle room. I would...

TonyA

Thank you so much for the help!; this information should definitely help in resolving the wet sumping issue.

Norton 961 massive oil leak.

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