Been noticing that after most rides, but not all, there is a oily stain on inside and top of swingarm and where it joins to engine block, sometimes tracks as far down as bottom section, quite often there is a stain on the end of the exhaust. Its like very hot or thin oil has leaked but its not that dirty the engine gearbox area are clean as is the oil tank as best I can see.
Thought it might be fuel blowing out the overflow breather pipe or buell snot from the head breathers, but they both drain into the exhaust wash.
Any ideas

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Buelling is exhillarating
But downhill bike racing is so terrifying it makes your arse grow teeth

it's fucked , give you a fiver scrap for it

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Feros Ferio

Don't listen to Nutah, it's worth more than that....Ill give you £20 for it.

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Valencia Orange XB12Scg - serviced by Maz 2018
Black P3 Blast - serviced by Maz and fixed by Maz in 2019

Jill knows what shes on i would take her offer

Is it tranny fluid from the stator cable grommet?

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If your dreams don't scare you, they are not big enough.

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FUBAR pilot

You only need two bikes in life-an S1 and a Multistrada!

Really don't know as it seems all a bit mysterious, as stated. But my immediate thoughts went to the oil tank itself.

I had two failure of the pipe/tube unions on my S1 before I replaced it with a Metmachex tank. The first was the lower pipe union that seemingly developed a leak after riding and dumped all the oil in the floor by the next morning, the second was the upper union (oil return, I think) that failed when I was out riding and covered the back wheel after finding its route down the corner of the tank and onto the swingarm just as you decribe. The weird thing was that the oil did not look that dirty, probably because it was a thin layer and hotter than hell.

So, I'd be checking the oil tank and its feed with insane scrutiny if I was seeing this now, although with the Metamatex tank, there are no rubber gromets to age and go brittle then fail with vibration/use. Which is why i got it, safety not bling!

Could easily be something else, but that is where I'd be pointing the microscope if the rest of the engine/gearbox looks clean.

2p

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Truly S1nthetic
Peccav1

Mine leaks a bit from there - collects on top of gearbox

I have used aerosol foot powder, or some similar spray powder, to put a light coating on areas in question. The origin of the leak will be much easier to pinpoint.

Keeps fungus off the bike as well...

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2006 XB12Ss..... 1998 S1W..... 1996 S2T
We do not need the help of our friends so much as confidence that they will help us when we need it. –Epicurus

Thanks for the ideas, I think the oil is coming in very small amounts from the tank Not shure if its a leak or hot oil migrating down the bit of tank behind battery from spillage when filling after a change
Mechmatex me thinks is the only way to go........next winters mini project.

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Buelling is exhillarating
But downhill bike racing is so terrifying it makes your arse grow teeth

I will have you know that Wales IS a mini project

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