Here is the lowdown. I parked my 1977 50v but accidentally left the gas line on. i have a leak coming out of the bottom of the carb so the gas slowly leaks out when on. i left it for a while and got back on and started up. at about a 1/4 mile it started stuttering so i pulled over to a gas station to see if that was the problem. i saw that there was gas still there so i tried to ride home to further inquire. it wouldnt start. there was no spark is my guess becasue i would peddle and no sounds were heard. i looked at the spark plug and it was carbonized to hell. i figured that was the problem. i started walking home and half way there i felt some resistance so i hopped on and started her up. she ran great. what was the problem? i think the head gasket is leaky becasue black fuid is sprayed onto the front fender and on my shoe. is that what a problem for what happened? or did i somehow flood something with gas by leaving the line on? please help.