I removed the air filter from the engine and picked up a K&N cleaning kit:
Cleaned, oiled, and ready to put into service:
Air filter back on the engine and ready to go:
Engine air filter
Matt's RV-7 Project
"We are still far from the ultimate goal, and it would seem as if years of constant work and study by experts, together with the expenditure of thousands of dollars, would still be necessary before we can hope to produce an [aircraft] of practical utility."