The service manual for my '07 Dyna references replacing the dowel o-rings when re-installing the head, but there is nothing shown in the parts book. It is kind of academic anyway, because the Cometic head gasket instructions says to omit those o-rings when using their MLS gaskets. However, I was just curious about these as there is nothing in the parts book and there is no groove for an o-ring on the cylinder or head.

 

There is a groove in the case for the lower o-rings. There is no groove up top because the o-ring fits into a space created by the OEM head gasket. The Cometic gasket fits tight to the o-ring so no o-ring required.

 

Hey djl do you use the o rings with the SE head gaskets?

 

Have never used the SE head gaskets. The way to tell is how the gasket fits to the dowel. If the gasket fits tight to the dowel; no o-ring. If the bore in the gasket where the dowel fits does not fit tight and leaves space for the o-ring; use the o-ring.