I had the same problem. And even though I was very careful to stretch out my entire spin halyard, untwist it, then rig it to the mast, after a few races it would start kinking and getting stuck in the tramp gromet again. Some guys have done as Robi said, which is to pull the core out for the distance from the hoist block down to the clete, minus say 6 inches for clete holding, and just run the hollow jacket after the clete, down on the tramp, through the gromet, back up through the snuffer sack to the belly patches. That is the cheapest and quickest way to fix it. You will need needle and thread to secure the jacket to the core where it will be in the clete, after you do the cutting and pulling of course.
I spent the money for a custom made spin halyard from Layline, the skinny part is 3mm dyneema, the fat part is about 5mm mafioli I think, or some soft weave, it's easy on the hands and doesn't kink up on the tramp. Mike Krantz can tell you what it is, he's made lots of them.