One thing i have noticed with all the older Hobie coments about having troble with raiseing the main. I had some troble too. Just bought a 79 hobie in great shape , but Putting up the main seem to be a issue to when it got to the top of mast. Heres what i found out. The beads were mushroomed and having troble going through the mast head and Sheave , and then troble at the halyard hook. The Halyard line itself was in great shape but the beads had the mushroom thing going on..I think its from years of wear. So i took a file to the mushroom part of the bead on the halyard line. I was careful not to hit my line and damage it. Anyway i also replaced the mast head sheave with a Corian Sheave that i made. With the filing and new Sheave it works like new. As far as the Corian Sheave it works just as good as Factory part. When i made these Sheaves i was very careful to make sure they matched the old ones..If i can help anybody out with getting a new sheave that i make get in touch with me....