I have a 1981 honda CB650C . I just got to start her after he winter break and she does not Idea , when started she goes direct between 4000- 5000 RPM and does not drop , i have tried with the slow speed screw adjuster appears that is to the maximum for her to drop to slow speed but if I tighten the screw it raises. CHoke is fine when I pull the Choke it raises higher and when i give it gas (throttle ) it raises over to 5000 rmp and then i drop the Gas ( throttle ) she come back to 4000 RMP , Not sue if its the air intake or anything else , the bike is good has only around 22,00kms on it and she starts up on the 1st shot with the help of choke till she is warm. I am just waiting to ride her but can;t because she is not dropping RMP. pls let me know what you think cud be the problem. tks