Has anyone ever had this problem? I just picked up a 2004 DR-Z400S and took it out for its first ride yesterday. I rode through some pretty technical areas in 1st gear. From time to time, the engine continued to rev after I had released the throttle. I had to neutral it and rev a few times to get it to come down. Second issue, which may be related, during normal riding I get spitting from the exhaust when I release the throttle. I say spitting as a mild use of the word backfiring. Any suggestions?