T.J.Falloon wrote:Apparently this is done to help drain the oil away from the rocker assembly. I can only presume to stop oil potentially flooding the tappet area and maybe burning it.
I am sure there are more knowledgeable members out there than I who know exactly why it's done.
There is a recommended modification to help drain the oil away from the rockers and valves. However, on your rockers the cuts look like an attempt to do this, but not quite like the manual recommends. All four rockers should have it, though, and not just the outer ones.