If it only does that when sitting, then a shutoff valve should take care of you. If it's flooding while running, you probably have an issue in the carbs that needs to be addressed.
1986 Yamaha XT350
2005.5 KTM 950 Adventure
1991 BMW 318is turbo track car
1989 Chevrolet Caprice Classic Wagon, TBI 5.7, NV3500 5-speed, lowered, etc...bike hauler