You should not see a jump like that at idle when you hook up the vacuum advance. Either you're hooking it up to the wrong place as Volaredon suggested, or there's something the matter with your carburetor such that the throttle plate is above rather than below the spark advance port at idle. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted
here for free download, and find tune-up parts and technique suggestions in
this post.
