In a message dated 10/8/2010 3:44:31 P.M. US Mountain Standard Time, shaun_mcgarvey at shaw.ca writes: If you've got '64-up carbs on it, and the vapor vent at the bottom isn't closing properly when you take your foot off, it will do this. Hummmm......Doesn't the vapor vent OPEN when you take your foot "off it"? Regards, Bob Helt