I don't know too much about this ski because it's my SIL but it's a Kawi, vintage around 2004, 3 cylinder 2 stroke with direct fuel injection and she asked me to help her. Several years ago she sucked a towline into her impeller and since then she has been havina knocking/clanking sound in her driveline at idle, above idle it goes away. The ski runs fine other than the noise. Any ideas?