Idles high in neutral, not in gear
 

I have a 1982 suzuki gs450ga. And yes it's automatic I just bought the bike. It idles super high in neutral but once in low gear or drive it idles normal any ideas why? Bike is in amazing condition otherwise would like to just get it running perfect thanks

Clean carburetor
 

Usually this is a clogged low speed fuel jet.

It's is good practice to remove clean and restore the carburetor each year.