I have a new to me restored 1962 VBB . The throttle does not engage the throttle slide. I have adjusted the bolt and nut on the carb body but it is still too loose. Turning the throttle to full on only move the throttle cable enough to touch the slide. How can I take up the extra slack? The Vespa was bought by another person who no longer has the paperwork of where he got it from so I don't know who restored it. The copy of the owners manual and the restoration guide book I bought do not show me how the cable is connected to the throttle tubes in the handlebars. Any help would be greatly appreciated.