Honda HRX217 leaking valve cover

So I used my Honda mower for nearly the entire season before it began to leak oil. I attempted to replace the RTV gasket without replacing the valve cover. Well, that only made it worse. I was forced to buy a new valve cover over the winter. Thought I had it buttoned up but it's still leaking oil. What a piece of shit. Does anyone have any tried and true repairs? I love the mower when it works, but I am getting tired of its unreliability.