Replace the o-ring on your dizzy.
Not at all a hard job, you could do it in half an hour. Make sure your dizzy is back in the right spot when you remove it. best bet is to mark it all out. The ring should be the same across all bigports. Or just go into a parts shop and get them to find you one the right size from the sample you bring in?
And i can't think of a replacement cable off the top of my head, there are some, someone else will post the right answer in a sec no doubts