i am going to do the oil change for my ages old GPX250 (2006) by myself (very first time!) I have everything ready except the washer. I know you don thave to change the washer every time, but considering it is my first time and the oil has never been changed since i got the bike. i wanna do a "proper" one. the question is i am not sure where i can buy the washers. I have never dealt with and dont want to deal with the dealer. I wonder if the wash is a standard size which i can find either in Bunnings or SCA? thanks in advance.