To replace the duckbill in the oil check valve for my Poulan XXV micro, I tried filing just the edge to get at the duckbill but ended up completely filing down to the brass insert. After replacing the duckbill, I opted to spread a stainless washer slightly and use it in place of the brass insert. The washer is slightly thinner so it allowed me enough material at the opening to crimp it over a bit. The hole in the check valve lines up directly with the hole in the case but I’m not sure which way the duckbill is facing or if it makes a difference. I then used 5w-30 oil.
I also fabricated a clutch removal tool because I’ve taken it apart so many times.
