I have the exact same problem with my 2012 300 sherco.
The clutch just doesn't seem to release as quick as it should although it does seem sharper when its cold.
So far I've changed the gear box oil and the dot 4. Also the plates also don't seem warn to that extent.
If you do manage to suss it out please please let me know.
depending on what it is your looking at. if its a small slit in the breather yep its ment to there stops vaccums forming in the breathers and in the carb.
or
my other thought if this is the petrol line from the tank and your worried about it being too close to the barrel of the bike and petrol evaporating. i know that they used to be shortented slighly inorder to keep them away from the barrel.
Hope this helps
