Dirty oil makes clutch slippy?

[kawashima]

My W650's clutch is slippy now. It slips when I open wide in 5th or 4th gear. But not in 1st gear .
I adjusted clutch wire but it's still slippy. I phoned and asked the mechanic, he asked me if I haven't changed oil for a long time. Yes, I've ridden 3000km after oil change, a little bit longer than usual.
Does dirty oil makes clutch slippy?
I have once burnt my clutch and changed them to new ones in Dec. 06.
____________________
own:2020 Serow 250
owned: 2012 YB125SP, 2008 TDM900, 2005 W650, 2002 LS125R, 2002 CB400SF, NS50F, C50 / Trip to UK(2009), Hokkaido touring(2013)

[stinkwheel]

Should be the opposite. Old oil is less lubricating.

A slipping clutch will make your oil dirty more quickly.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[kawashima]

Thank you for letting me know!
____________________
own:2020 Serow 250
owned: 2012 YB125SP, 2008 TDM900, 2005 W650, 2002 LS125R, 2002 CB400SF, NS50F, C50 / Trip to UK(2009), Hokkaido touring(2013)

[kawashima]

I'm going to change oil this weekend, and adjust clutch wire (crank case side), try to bring biting point more closer to the handle bar.
But if they don't solve the problem, what should I do?
What I'm feeling is W650 doesn't have strong clutch springs from the original...
____________________
own:2020 Serow 250
owned: 2012 YB125SP, 2008 TDM900, 2005 W650, 2002 LS125R, 2002 CB400SF, NS50F, C50 / Trip to UK(2009), Hokkaido touring(2013)

[stinkwheel]

Sometimes the brand of the oil can make a difference. It may be worth trying a different brand.

If you have a service manual, the free length of the clutch springs and the thickness of the plates can be measured to check they are within tolerance.

Sometimes the surface of the clutch plates can become "glazed". They can be removed and lightly rubbed with fine abrasive paper to remove the glaze.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.