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.

Norton 961 massive oil leak.

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