Over the last few months I have noticed a very slight oil drip on the lowest point of the crankcase (neaxt to oil filter).
Last night I think I located this mystery oil leak by running the bike for about 20 mins in my garage (I waited until my missus went out as she would have given me a real earful for this!). It's a bit weird, it appears to be coming from the clutch casing casting - about mid-way between the oil sight glass and the clutch cover - not from a joint. It appeared initially as a slight wetness on the surface of the casing and then progressed to be a very fine "run" that went down to the oil window and then progressed down around the filter housing and onto the crankcase joint where it dripped down onto the front pipe! So I reckon the casting is porous or has a pinhole in it.
Has anybody else had this??
Also, is the clutch casing the same for all 4 valve ( and 2 valve?) models?
Not had a porous casting,but had a slight oil leak that ended with a "drip" around the filter and onto the exhaust.Eventually found the source by drying the cases and applying talcum powder.Traced the damp line back to the clutch pushrod.
Have had the problem of an oil leak from clutch pull rod when my old 996 was serviced by Ducati L***s. Oil blowing back all over the rear wheel during the 2800 miles on the Run to Sun in 2001. On the return home located the problem to clutch pull rod being inserted the wrong way around so oil seals didn't!
Point is, apart from being wary of who services bike, was that the source of the leak was very difficult to locate and like you it seemed to be coming from a part of the casing near the oil sight window.
Might be different in your case, but check the oil seals on the pull rod - it is very easy to do (just wish I had done it before I replaced oil lines and trashing my tyre).
Had a simalar problem on the rear cylinder of my 748, the plug hole would fill with oil, had to get a second hand head fitted, cured the leak, but yes I would go with the porous casing & replace it, should be cheap enough from ebay.
Definitely not the clutch pushrod - that was the first place I looked! I have done all the usual troubleshooting stuff involving talcum powder etc - no signs from cylinder base/head, oil pressure switch, oil filter, oil cooler hose joints etc etc - I am 99% sure it's coming from the casing itself! Hopefully will get a spin on the bike this weekend to see if my temporary repair has plugged it up (I have used some Oilite Stick - it's stuff we use in the airline business to plug up running fuel leaks on our Jumbo's...).
Does anybody know if the clutch cases on 2 and 4 valve motors are the same?
I was wrong...it's not a porouse casting - it's either coming from the big seal behind the clutch basket or from the casing joint face. This confirmed by the expert Wilf at Motorapido on Saturday. Roy (Doogalman): I have sent a begging U2U (or whatever they a re called now) asking if I can borrow your clutch tool (again!).