I recently bought a 1973cb 350ss, the bike is in good shape with only 21000 miles. However I am having a little bit of trouble when I start to ride the bike. It will start up good usaully first kick, and it will idle around 1300 rpms, if I rev it at all past 3000rpms it will not come back down to its regular idle. The same thing happens when I am riding it when I pull in the clutch it will rev like a bat out of hell(4500-5000rpm) the engine also gets quite hot. I think I might have a vacuum leak but I'm not really sure. I am still learning about bikes so any help would be good!