Recently re-stored a 1999 XR 600r...installed a FCR MX carb...bike runs great, jetting is on...one issue. After each ride, the vent tube from the bowl, leaks out 4-5 drops of gas...cannot be right. Any ideas on what would cause this....does not do it any other time but after the bike is stopped and the engine is off. If the engine is running no leaks from the vent. Thanks for your help.