I'm trying to figure out what sealer to use when I bolt my lower gear case back together. It's on an old 6hp Evinrude. I've heard to use a hardening sealer, and also heard just regular RTV that stays flexible and is non-hardening. Does it really make much difference? Also, does anyone know where I could get a used recoil spring for 1967 6hp Johnson? Or anything alittle cheaper than the $38.00 one I found locally?