A Harley breather separator upgrade (p/n 25329-91) was first used in April of 1991. It is a spiral, plastic air/oil baffle that is installed inside the cam gear cover steel breather tube. It is a retrofit part on 1992 and earlier bikes and is recommended any time the cam cover is off. Use it in conjunction with the OEM breather gear (p/n 25310-82a) or the S&S gear (p/n 33-4236) on any motor subjected to high rpm use.

This is for 1991-UP bikes.