I have a Polaris Trail boss 250 with ok spark and 105 Lbs of compression and it will not start even with a can of starting fluid. I noticed that around the first bend of the exhaust that there is a lot of oil built up if that helps. I noticed when I pull the cord the gas/starter fluid sprays out of the intake side of the carb.

 

compression should be 125 to 135+-. I have seen them run with less though. it would not take much starting fluid to fire it up, as too much could lock it up. it wouldn't hurt to charge the plug if you have not already.