head bolt retorque.

[Paul Sutton]

Machine, I matched my brass washer diameter to whatever the rubber coated washers were. Brass worked fine with no leaks. I prefer its mechanical properties, Copper seems too soft.

 

[5twins]

Before Mike's came along with the brass ones, we used these Suzuki washers .....

https://www.partzilla.com/product/suzuki/09168-10017