Jib flapping in higher winds
Last weekend I was on a starboard tack, close hauled, and the wind was about 18-20 knots. The jib was noticeably oscillating, similar to leech flapping but seeming to be the whole sail. It doesn't do this on a port tack. I would like to tune it out as I don't think it's healthy for the rig.
The boat has roller furling. I did notice that the port jib track was set further aft than the starboard ones.
OK, I admit it, I'm not sure what to do with them. I've just set them in the middle.
So my questions are, how to tune out the jib flapping
Secondly, how to set up the jib leads in general.