The old victa metal type carby (3F,3L,3Q & 3S) should stop when you reduce the throttle down to minimum. If it does not then you need to look at the settings for the carby.
Detailed information on the settings for the carby are in the parts list and manuals area of the forum.
Regards,
Bruce
Please do not PM me asking for support. Post on the forums as it helps all members not just the individual.