I bought a used ski. Runs great until you shut it off. I found that after riding for a few it wont restart. If you let it sit for about 15 minutes we are good to go. When you crank it almost smells like its flooding (gas smell). I replaced the plugs and found out that when it wont start i can pull the rear plug, blow out the cylinder and replace everything and it starts right up. So my question is this a vapor lock issue or is it the needle in the carbs causing the cylinders to flood? Thanks for any input