two K1300S bikes, S1000R & Vespa 150 Primavera clown paint job
I have Orings if you want a couple. The OEM clamp has a mechanism to keep it open until seated then snaps closed. This often fails and the lock clip on the female portion cuts the oring. You need to hold it open until the male part is all the way home. Do not over tighten that female fitting that fits into the gas pump flange. The paste acts as a lube as well as a sealant. You can split the flange. The flange can split from old age also it seems. Also wet the Oring with some gas or a super tiny bit of rubber lube so it will slide.