I have been searching since yesterday for some definitive information. I am working on a buddy's 2008 Polaris dragon 700. Wont start at first until I prime the cylinders with a little mixed fuel. Then it fired right up and ran like a champ. Shut it down and did some preseason work on it and before I left the shop I started it again just to see. No problem, fired up first pull. Let it sit overnight and today it will not start again. So my question is ... is it most likely the check valve at the fuel pump? Is there somewhere else the fuel pressure can bleed off? Has great spark. Fuel filter doesnt seem likely because it runs so good once started also only 800 miles on the sled.