I remember old Polaris tech talking about the crank seals and yu indicating there is a small wiggle, have to agree the bearings are a place to start. When doing a complete rebuild, using old parts just doesn't work in most cases. When I had my 3-1999 Scrambler 400's, I went through the motors from bottom up, took cranks into a machine shop had them tested, bearings also, any out of tolerance got replaced. Spec's are very important when doing motor work, and cylinders are the same, thousand's out of spec means you have problems. Back to your issue of not getting Gas, still sounds like something in the carb or reeds not pushing the Gas into ignite stage. You have checked your coil for spark, and is a strong spark?