Have a 2007 Big Bear 400. I never ride it. It sat up I changed all fluids and such. Started right up but smokes white horrible. Like blind you. Rebuilt the carb already. Any ideas or suggestions on what this is?

 

Compression test and leak down can help tell what shape the engine is in. Low compression can mean worn rings or leaking valve guide seals could be the cause of the smoking,but a leak down test can track it down closer.