Help Identify Oil Leak Please - 2003 SV60S

Grateful for suggestions as to the most likely cause of an oil leak.
Background:
- rode bike Northumberland to Hull (155 miles) noticed oil on left side, on sprocket cover, above it and on the casing. Like blood, always looks a lot, due to being thrown around under pressure. Cleaned it up (at ferry terminal) could not see an obvious source. Boarded ferry.
- a dozen or so drops on ferry floor in the morning. Left ferry, topped up with oil to top line on siting glass at service station 100 yards away. Drove first 50 miles slowly, covering the clutch lever (!) and checked twice, no apparent drop in glass, but very evident in same places on the bike. Drove another 75 miles, same result. Drove another 120 miles home, loads of oil in same places on bike but level barely moved.
- cleaned bike, left in garage overnight. Maybe 3 drops of oil on floor in the morning.

Seems it loses more and flings it about under duress of riding. Output seal? Other likely candidates?
Should say I'm pretty basic with mechanics and only mentioned the output seal as it came up when I did a search here. Goes without saying that it'll be looked at and sorted by a mate who's handy, just wanted to get the benefit of any good souls out there who have maybe had similar and can save me time.
Thanks in advance.

[Biker Biggles]

There are a couple of crankcase breather pipes that go to the airbox.One is very close to your oil leak so check that is ok.

Clean it all off and put talc everywhere, leave it over night and it should now be obvious where its coming from, or at least narrow it down.

[Spanner Man]

Good morning all.


The most likely candidate would be the clutch pushrod seal. I have known of a few failures over the years.


Cheers.

[DavieSV]

Clean the oil cooler pipe with the plastic protector on it. Then start the engine and look closely at the ends of the plastic bit to see if oil weeps out.
The pipe corrodes under the plastic and then leaks under pressure.
Mine did this in Wales with very similar symptoms to yours.
I was surprised how far the oil had traveled from the leak!

Thanks guys.
- are the crankcase breather pipes easy to get to/see? Where should I look? What is there function normally?
- I'll try the talc tip.
- Isn't the clutch on the right side of the bike? Could a failed clutch push-rod seal result in oil on left side of bike, but none on the right side?

Thanks again, good to know sv friends are willing to help.

UPDATE

The breather tube from the back/top of the crankcase was completely detached. Have pushed it back on, tightened with circlip back in place and taken for a test drive, for a couple of miles at high rpm and road speed, after reaching normal operating temperature ....... no evidence of leaking oil.

Hopefully, this has been the problem. I was surprised how much oil seemed to escape this way. As I said earlier, I'm very limited with mechanics. What exactly is this breather pipe for? Surely that oil doesn't go into the airbox? What does it do? Does it's detachment at the crankcase side make this much difference?

Thanks for all the suggestions. An explanation about the breather hose crankcase to air box would be appreciated, just to help me understand.

Cheers.

[yorkie_chris]

Yeah that's pretty typical. There's a catch can as part of the airbox to trap the oil and let it dribble back into the engine.

Basically because the 2 cylinders are out of sync by 90 degrees a proportion of the crankcase volume has to move in and out of them every rotation of the engine. Plus a bit of combustion gas that escapes past the piston rings. Because lots of oil gets splattered about inside the engines some of this vapour gets carried out with it.

Thanks Chris, appreciate your help. I can understand the release of vapour. Mine seemed a lot more than that, with definate oil 'runs' or 'streaks' down the crankcase and sprocket cover. Mind, I did do some 400 odd miles in extreme conditions, at relatively high rpm.
I'll keep an eye over today and tommorrow before I declare it 'fully fit' ...... fingers crossed.

[yorkie_chris]

If you leave a breather off it p*sses everywhere, I've done it. It looks like a lot of oil lost.