A couple of things I noticed riding my 2011 EC300

[RONALD BRUNDIGE]

Have you removed the basket and greased or lubed the washer on the back side? I have had plenty of these bikes, never had an issue except in 07 when I was racing mx and forgot to put oil in the bike. oooooppppppppssssss my fault, and I took it apart and pre lubed everything and it was fine after that. Not saying that you have no oil or low on oil but that was the only issue I have ever had with a squeaking clutch on a gasser. Maybe try using green colored springs from the 450? Different oil?, clutch rod?, bleeding fluid or replacing it? or just pound it till something breaks and then you now what it was lol! Good luck on trying to break it cause I have tried and it is tough!!!!!!