New to Harley Engines: Why are there openings in the Rocker Box Covers

[Smuve]

I'm new to working with Harley Engines. On my 2000 X1 there are rectangular openings in the rocker box covers. I can see a lot of dirt and debris down in the boxes. Should these rectangular openings be plugged? I don't see a plug part in the parts catalog.

[Blks1l]

No plugs go in those spots, just the way they were designed.

[Aesquire]

For airflow and cooling, hose them out, perhaps a foaming cleanser designed not to harm paint & gaskets. Or just compressed air.

Simple Green foaming bicycle cleaner in an aerosol can works for me. Rinse well with clean water.

[Smuve]

Thanks for the info! I'm having a lot of questions as I get deeper into this restoration. Finding some answers in the old KV.