Need Help Troubleshooting a Vintage Honda 1975 CL360

I recently bought my first bike and purposely got a project bike to not only try and teach myself how to work on engines, but also just because it’s pretty damn cool. I finally got the thing to run yesterday and after riding it around my neighborhood for a bit I realized that one of the gas lines melted to the exhaust and died. After I replaced and secured the line, the bike doesn’t want to go above ~2500 rpm’s, but will sporadically shoot up to almost 4000 at times. I looked online and had a hard time finding out what the reasoning for this could be.